DE2153123A1 - Method and apparatus for analyzing the size of particles - Google Patents

Description

jfATRNTANWALTB

DR. O. DlTTMANN KL SCHIPP DH. A. ν. FÜNBR DIFLi. ING. I ^J. STOLE

8 MUNICH ΘΟ MARIAHILFPLATZ 2 ft S

DA-4494

Description of the patent application

of the company

COULTER ELECTRONICS LIMITED High Street South, Dunstable, Bedfordshire ,. England

concerning

Method and apparatus for analyzing the size of particles.

Priorities: October 27, 1970, USA, No. 84,440

December 24, 1970, USA, no 101 325

February 8, 1971, USA, No. 113 165

February 9, 1971, USA, No. 113 920

The invention relates to methods and apparatus for analyzing the size of particles, and more particularly to one Apparatus in which analyzes of particle systems using the Coulter measurement principle are carried out in the manner that more accurate information about the particle size than before is obtained.

The Coulter-Hess principle is described in US Pat. No. 2,656-508. According to this principle, when a microscopic particle in a bus board occurs in an electrolyte due to an electric field with small dimensions approaching those of the particle

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is sent through, a momentary change in the electrical impedance of the electrolyte in the contour of the field. This change in impedance transfers part of the excitation energy into the associated circuit, so that an electrical ¹ signal is created. This signal is recognized as a reasonably accurate indication of particle volume for most biological and industrial purposes. Devices taught in U.S. Patent 2,656,508 have been used to count and size particles in biological fluids, industrial powders and pulps, etc.

* · In commercial embodiments of the Coulter principle device, the electric field with small dimensions has usually been formed by a microscopic, right-cylindrical passage or opening between two bodies of a ^: liquid in which the particles to be analyzed are suspended. The electrical excitation energy is applied to .these . Bodies coupled with the aid of electrodes, which are each located in the liquid bodies, the opening being formed in an insulating wall between the bodies. The suspension ί is allowed to flow through the opening, causing the particles ^! carries with the flow. The instantaneous changes in impedance produced by each particle as it passes through the opening creates electrical signals. The electric field is concentrated in the opening and normally has an electric current which flows through the opening together with the physical flow of the suspension.

■ By counting the generated signals, the j Count particles passing through the opening. By discriminating between different pulse amplitudes can size analyzes be performed. The present invention relates mainly to size analyzes and has set itself the important task of to provide a device with which measured values can be obtained with high accuracy over the particle size.

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It is known that "long" openings produce results that superior to those of short openings in terms of size measurements when the bandwidths of the associated amplifiers are correspondingly reduced ". A long opening is considered to be one where the length is greater than the diameter. The common Coulter opening is relatively short, i.e. its length is equal to or smaller than its diameter.

The reason for better size information in the case of long openings is that the electric field is most homogeneous and the most homogeneous halfway through the opening, ie at the point furthest from the entrance and the exit of the opening Has power distribution for all paths through the opening. The longer the opening, the closer the uniform field distribution is approximated at this center point. At the inlet and the outlet of the opening, the current density is greater at the edges of the opening and correspondingly lower at the axis of the opening. To explain it, it should be noted that the current paths, apart from the axial path, are tracked both from the sides of the opening and from the front. The lower on-axis current density at the entrance and exit results in a lower instantaneous signal than if the particles enter the opening by other ways _: enter and exit. In other words, the current ■ _ is tight at the corners of the mouth than at the axis. !

Another important phenomenon is that the flow | speed of the electrolyte and therefore the velocity of the particles on an axial path slightly greater than the '■, is closer to the edges of the opening lying paths or paths extending outside the center, because the liquid does not have to change their direction when it passes through the axial center of the opening. The resistance to the flow is a minimum on-axis as it is surrounded by a moving layer of liquid that is at essentially the same velocity.

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According to various embodiments of the invention, the Particles passing through an opening are checked electronically to find out and make sure which of the Particle with the best approximation has passed through the opening on the axial path. These are the only particles which are detected by the device, the other particles are not evaluated. The electronic option is on the fact established that the axial »'. Orbit following particles the Spend the least amount of time in the contour of the opening, and that is why their corresponding impulses have the shortest duration. Theoretically, all of have particles passing through the opening caused impulses regardless of the particle size. same duration. Because of the reasons given above, this is in; not correct in practice. The impulses of such particles, which pass through the opening outside the center, have, (usually a longer duration. j

The partial pulses are checked by the fact that their pulse duration. at a specific part of their amplitudes amount fixed \ is provided. The resulting measurement signal is then converted into a ■ pulse whose amplitude is proportional to the ^duration: of the measurement signal is. This amplitude is then compared with certain criteria to ensure that the original pulse was of such a size that it conforms to a pulse height. ■ analyzer can be passed on or it can be discarded; j must. j

I - I

Use the first exemplary embodiments yet to be described a manually controlled circuit to set the basic threshold value after which it is determined whether a given Signal to the output v / is passed or blocked. As a result, test and adjustment measures are necessary that are practical for each use of the device must be carried out. The following embodiments use a circuit that embodies the Need for manual adjustment and an automatic one

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Has memory device that responds to the duration of certain previously transmitted signals and therefore on itself adjusted to a certain pulse duration value.

Other preferred embodiments and improvements of certain embodiments relate to preventing the sensor from picking up a subsequent particle pulse during processing of a previous particle pulse so that the particle pulses do not trigger the sensor and a pulse immediately following the previous one does not actuate the sensor until the analysis is complete. '. ^;

• Γ

Other preferred embodiments relate to the transmission of complete pulses through the sensor in contrast to the transmission

. Carrying regressed or artificial impulses that are generated by \

are derived from the complete particle impulses. ;

Another embodiment performs the Teilchenimpulsmessung out at a time in which the particle is located halfway] through the opening. The associated pulse amplitude will be referred to as center-point amplitude \, which is often a more accurate measure ■ the particle size, because the spikes _t closer to the front and the rear edge of the pulse are not measured.

i

Two further embodiments relate to sensors for derivation;

j of a pulse duration measuring pulse, the duration of which is in one case

■ from the tip of a particle pulse to a partial value of the

■ amplitude of the same and in another case from the point in time ' • the maximum slope of the leading edge up to a point in time:

the maximum slope of the trailing edge extends. I.

According to the invention is therefore a method for analyzing the size of particles for scanning the pulses generated by the particles, which are generated when particles pass through the detector opening of a Coulrer measuring device, the method

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■ f t

distinguishes between those particles which move along the axis of the opening when passing through the opening and those particles which move outside the axis of the opening when passing through the opening, characterized in that the duration of at least a predetermined part of each particle-generated pulse is a predetermined partial value of its amplitude is measured that a pulse duration measuring pulse with constant amplitude and predetermined duration is derived from the fact that the pulse duration measuring pulse is converted into an electrical quantity with such an F value that is proportional to the duration of the 'pulse duration measuring pulse is that an electrical effect is generated _} which represents a reference value for a maximally desired value of the pulse duration measuring pulse, the reference value between ^ electrical measured values, i.e. those particles which pass through the detector opening outside the axis of the opening, and electrical readings below which represent other particle-generated pulses, from which pulse duration measurement pulses with shorter pulse duration than the maximum value of the reference value are derived, that each of the electrical measurement values is compared with the reference value and thereby an excitation signal of a first type when the electrical measurement value exceeds the Bek tensile value does not exceed, and an excitation signal of a second 'type is generated when the measured value exceeds the reference value, .that.an electrical signal from each of the particle-generated Im- ^; jpulse is derived and that each of the derived electrical _:

is allowed to pass or blocked, depending on the; ■ whether it is an excitation signal of the first type or the second!

'Type. J

According to the invention there is also a device for analyzing the Size of particles with an axial trajectory sensing probe for use with a Coulter measuring device, in the particles pass through a detector opening and particle sucked Generate pulses, whereby the particles, when they pass through the detector opening closest to the axial path, generate desired particle impulses with such amplitudes,

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which are in the best approximation proportional to the respective particle sizes, so that the desired, particle-generated pulses have a "certain approximate pulse duration, and the particles that pass through the detector opening on paths that are offset from the axis, other particle pulses with such amplitudes which are not necessarily proportional to their respective magnitudes, and have such pulse durations which tend to have longer pulse durations than the determined approximate pulse duration, characterized in that the sensor is constructed and arranged in such a way that it responds to the desired particle pulses in a first manner and responsive to the other particle pulses in a second manner and includes: an input port and an output port, a channel for passage of electrical signals between the ports, a switch in the channel to control whether an electrical signal is present at the output port on occurs, the input port being configured to have the desired and other particle-generated pulses applied thereto, measuring means for measuring the duration of at least a predetermined portion of each applied particle-generated pulse at a predetermined fractional value of the amplitude thereof, wherein the measuring device is constructed in such a way that it derives a pulse duration measuring pulse with the measured pulse duration and a constant amplitude, an electrical converter for 'converting the pulse duration measuring pulse into an electrical quantity with a value that is proportional to the duration of the pulse ^! is an electrical device for generating an electrical effect which represents a reference value for a maximum desired value of the pulse duration measurement pulse, the electrical device comparing the electrical variable with the reference value and an excitation signal; first T; / pes if the electrical quantity does not exceed the reference value, and generates an excitation signal of a second type if the electrical quantity exceeds the reference c-v / ert, and a circuit to send each of the excitation signals to the switch

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2153-23

to apply in the channel to allow only the passage of the electrical To allow signals to the output port that are generated by the desired, particle-generated pulses are derived.

Furthermore, according to the invention, a method for scanning particle-generated pulses which are generated by particles passing through a detector opening of a Coulter measuring device, wherein the particles, when they pass through the detector opening closest in an axial path, are desired partial- ' generate chenimpulse with amplitudes DLE pro- in the best _{approximation:} the relative sizes of the particles are proportional so that the *. desired, teilchenerzeugten pulses have a certain proximity 'as pulse duration and a maximum acceptable number of peaks ■, and wherein generating the particles hindurclsfc'reten through the detector aperture in relation to its axis shifted path curves, other particle pulses with such amplitudes that do not necessarily are proportional to their respective sizes and have more than the maximum number of peaks and / or pulse durations which tend to be longer than the determined approximate pulse duration, characterized in that the number of peaks of each particle-generated pulse and / or the duration of at least one predetermined part of each particle-generated pulse is measured at a predetermined part value of its amplitude, '. liaß-the number of peaks and / or the duration with a maximum

1 - J

Reference value for the number of peaks and / or the duration: is compared, an excitation signal of a first type if the pulse measurement does not exceed the reference value, and an excitation signal of a second type is generated if the pulse measurement exceeds the reference value that an electrical signal from everyone. ; particle-generated pulse is derived, and that the derived; electrical signal is either allowed through or blocked, depending on whether it is an excitation signal of the first type or the _; of the second type. ,

Finally, there is a device according to the invention for analyzing

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the size of! particles with a sensor for an axial trajectory _v for use with a Coulter measuring device, in which particles pass through a detector opening and cause particle-generated pulses, for carrying out the last-mentioned method, characterized in that the sensor is so constructed and is arranged to respond to the desired particle pulses in a first manner and to the other particle pulses in a second manner and comprises: an input terminal and an output terminal, a channel for passing electrical signals between the terminals, a switch in the channel to controlling whether electrical signals appear at the output port, the input port being configured to generate the desired and the other particles; Impulse v applied to / ground, a Heßeinrichtung · for measuring j is the number of peaks of each teilchenerzeugten pulse and / or \ for measuring the pulse duration at least one predetermined ex \-section of each applied, teilchenerzeugten pulse at a predetermined part value of its amplitude, an electric A -! direction for generating an electrical effect, which is a reference value for a maximum desired value of the number of peaks. and / or represents the pulse duration measuring pulse, the electrical device comparing the number of peaks and / or the pulse duration with the reference value and an excitation signal of a first type if the pulse measurement does not exceed the reference value, and an excitation signal of a second type generated when the i pulse measurement exceeds the reference value, and circuitry to apply each of the excitation signals to the switch in the channel! to ensure that only such electrical signals pass through to the outlet! To allow output connection, which are derived from desired, particle-generated pulses. · J

Embodiments of the invention will now be described with reference to the accompanying drawings. Show it: . ^!

Fig. 1 is a block diagram of the device according to the invention, in '

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- ίο -

the one /

.. · * inventive sensor for an axial path is used;

2 shows a schematic representation of the opening of a Coulter measuring device, the trajectories of various particles being shown through the opening;

Fig. 3 is a diagram showing graphical representations of particle impulses shows that of the passage of the particles of Figure 2 along the paths shown by the opening stem;

4 shows a block diagram of a "sensor for an axial trajectory, where "the sensor has an analog design;

FIG. 5 is a diagram from a series of graphic representations; on the same time scale, showing the different waveforms ^[ in the sensor shown in FIG. 4 which result from the processing of the two particle pulses in the sensor; ·

6 is a block diagram of a modified embodiment Play of the sensor for an axial path, I the sensor being digitally constructed;

7 shows a block diagram of a sensor according to the invention: -for an axial path, which has a memory for the minimum pulse durationP ^ inen clock generator; ; Figure 8 is a diagram of a series of graphs; on the same time scale, the different waveforms' feel in the one shown in Fig.7? represent that of originate from the processing of the two particle pulses in this;

9 shows a block diagram of a modified embodiment the sensor shown in Figure 7 for an axial path course; !

Fig. 10 is a diagram of a series of graphical representations, which result from the processing of the two particle pulses by the sensor from FIG. 9;

Fig.11 is a block diagram of one opposite that shown in Fig.7 modified embodiment of the

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Sensor for an axial beam path, which has a heating device has for the midpoint amplitude;

Fig. 12 is a diagram of a series of graphical representations, which occur when the two particle pulses are processed by the sensor shown in FIG. 11;

Fig. 13 is a block diagram of another embodiment of the sensor for an axial trajectory, in which peak and partial value amplitude measurements for the Determination of the pulse duration is used;

14 - a diagram of several graphical representations which, when processing the two partial pulses! result from the sensor shown in Figure 13; [

Fig. 15 is a block diagram of a further embodiment of the sensor for the axial course of the path, for which the j maximum slope of the leading edge and the trailing edge of the pulse used for pulse duration measurement ι will; and

Fig. 16 "is a diagram of multiple graphic representations in the processing of the particle _pulses.:. Arise by the sensor shown in Figure 15 S

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Γ "
I.

- 12 -

A device constructed according to the invention is shown in FIG. The block 10 is a Coulter particle analyzer, the
usually made up of a slide, a detector, and a
Counter exists. The output of the analyzer is coupled to the input port 12 of the axial trajectory sensor 14 which is the primary object of the present invention. The slide of the Coulter analyzer 10 has containers
Eohr with the orifice, the fluid system and the electrodes on. The detector contains the circuitry that generates the particle pulses. The counter can be any device ψ, responsive to the particle pulses. It can be omitted if
only measurements of the particle size should be made is
however, shown to indicate that since the probe 14 has many
Impulses, it is best to do any counting before "relaying the. Particle impulses to the probe. The
The sensor has an output terminal 16 from which the particle pulse signals are passed on to a pulse height analyzer 18 in order to make the particle size measurements. ,

Fig. 2 is a schematic representation of an opening that the
Forms scanning means in the measuring cell of the electronic Coulter particle measuring device 10, and which is immersed in a liquid, with particles passing through the opening of the leaflet. The leaf is marked with 20 and the opening itself with 22 ^; designated. The measuring liquid passes through the opening 22 from
right to left through and leads the particles into suspension,. with while she moves. The orbits of three particles X, Y, Z ^! are shown at 24, 26, and 28, respectively. The tracks are for the purpose of ^; Representation intentionally chosen so that it is considerably un- ^! distinguish. The signals or particle impulses produced by such
are generated in one pass are shown on an identical time scale in Fig. 3 as graphical representations X, 1 and 3,

The particle X runs almost coaxially to the opening 22 on the Lane 24. The speed of the passage through the opening Liquid is a maximum at this point and the

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Current density distribution along the track is most uniform. Consequently, the resulting pulse 30 in FIG. 3, as shown in curve X, is simply a bell-shaped pulse, the duration of which is proportional to the length of the opening 22 of t ^ - % 2 and whose amplitude is in good approximation proportional to the size of the particle is. Although the amplitude can be viewed as a voltage, it should be noted that the pulses and signals could also be current waves. '

Particle Y passes through opening 22 on a diagonal path 26. First of all, it should be noted that its path is longer than the path 24 when it passes through the opening because it is inclined at an angle. Second, at the point where it entered the opening, ie at the edge at 32, the current density is much higher than the current density closer to the axis of the opening. Consequently, the beginning of the pulse 34, which is generated by j this particle, has a higher amplitude and also probably begins a little before the pulse 30. If it is practically at the same time t. starts, "he hears later than at the time '. tp point because the residence time of the particles long in the opening. As shown, occurs a peak at 36 due to the effect of the high current density at the corner 32, and a smaller spike at '38 created as the particle leaves the aperture as it approaches the high current density at corner ^! 40. j

The particle Z passes through the opening 22 on a ratio; moderately straight line; in this case, however, it moves quite ' close to the wall 42 of the opening. The resulting pulse 44 has two peaks, one at 46 passing through corner 32 with its ho-j hen current density is generated ^ and another at 46 *, which is caused by it causing the particle to pass through the high current density at corner 48. In this case that remains Partial longer than in time t. - to in the mouth because the velocity of the flowing liquid close to the wall

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'- 14 -

is less than in the middle of the current. This is a well known one Phenomenon "in the case of liquid flows through openings.

In these three cases it can be seen that the only momentum that most accurately represents the size of the particle is that
is generated by the particle passing through the center of the opening 22, ie by the particle X. According to the invention
a circuit created to receive pulses of the other types on the
To sort out based on their duration, since it is clear that only the
k pulses of short duration coming from through the center of the opening
passing particles are generated which have the most representative waveforms.

A device is created to switch between the different ^! to differentiate between types of impulses, which are shown in the graphic representations of Fig. 3 ©. The basis for the _sub: divorce in Vorric-Pla, which in conjunction with Figures ^4! and 5 is the analog construction, while the
Basic construction in the device shown in Fig.6 is digital. ; The analog construction is a bit more flexible.

.'The block diagram shown in Fig.4 shows a sensor for the

jaxial trajectory, which is the basic circuit for realizing _; ilichung the purpose of the invention is used. For the purpose of
Explanation assumes that two particles are checked,

For example, the particles X and Y of FIGS. 2 and 3 · The resulting waveforms of the pulses in the circuit are shown in FIG. 5 _: all on the same time scale. I.

ι i

The sensor 14 of FIG. 4 is characterized by means of analog construction in order to distinguish between pulses of different duration, the desired pulses being selected on this basis _! selects v / earth and allows it to pass through the device.
If an output pulse occurs, it always has the same amplitude as the original pulse, for example the
Pulse 30 of Figure 3, however, has a predetermined duration, the

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^! -15-

is determined by the electronic characteristics of the circuit. Since the 'particle size information is paramount, the duration of the Output pulse insignificant, and according to the operation of the device all output pulses have the same duration. The input terminal 12 is applied with a pulse train from a device comes, which is constructed according to the teaching of US Pat. No. 2,656,508. These impulses are as such as a result of a A particle passes through an opening, for example the opening 22 shown in Figure 2, generated and have different. Amplitudes, pulse durations and pulse shapes.

The pulse train received at input terminal 12 has been amplified prior to being passed to the sensor, this being accomplished by circuitry normally included in the detector of a conventional Coulter analyzer 10. You '. However, this can also be done later.

The signals appearing at input port 12 are particle determined pulses and are applied directly to pulse stretcher 50 and pulse delay line 52. The purpose of the delay of the signal, as will be seen shortly with reference to the waveforms of Figure 5, sufficient to allow the pulse stretcher time to a level set, against which the actual pulse can be compared to provide an accurate measurement of its \ duration to achieve. The duration is at a partial value of the ^pulse: height measured so that the results are obtained with the greatest accuracy. In the exemplary embodiment shown and described, half the pulse height is selected for this purpose, in other cases: the value can differ from this partial amount. Even with levels at 3/4 · the pulse amplitude, Er-! result achieved.

In the graphic representation A of Fig. 5, the two partial ; /. ~ nimpulse 30 and 34- shown, these impulses on the Ei j! Jangs connection 12 occur one after the other. According to the one described here In theory, it is desirable to adopt pulse 30

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and to block impulse 34, since the latter has a duration which is considerably larger than that of the earlier pulse, so that it is almost certain that its amplitude is not close enough is proportional to the size of the associated particle.

Pulse 30 is now considered. The pulse stretcher 50 causes the pulse maintains its maximum amplitude X during a period after the input pulse has fallen, so that the output of the pulse stretcher that appears on the channel 54, from the extended pulse 56 of the graphical representation W position B of J ¹ Xg.5 exists.

This stretched pulse 56 is attenuated in the attenuator 58 and appears on input line 60 of comparator 62. The resulting decrease in amplitude is the partial amount which is selected for use in the probe 14, and the resulting pulse is at 64 on the graph G. The factor 1/2 is selected as the damping, so that the amplitude of the plateau of the pulse 64 is half of the Amplitude X is. Also shown in graph C is the delayed pulse 66, which is pulse 30, however occurs at a later time on line 68 as a further input to comparator 62. The duration of the pulse 30 is in

! • typical cases see 15 Ai, and the delay time, that _is: for the time of t. - t ^, selecting an appropriate ^value: see, for example, 20 Ai. This depends on the physical characteristics of the opening, including its size, the viscosity of the electrolyte from which the suspension of the particles is made, and the pressure drop across the opening.

• 'The delayed pulse -66 exceeds the plateau of the damped one Momentum between the times t ^ and t, -, and consequently generated the comparator 62 only has an output if this is the case. The output occurs on line 70, and is the input signal to an integrator 72. The output

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of the comparator is a Reenteck wave 74-, which in the graphic Representation D of Fig..5 is shown, and difF ^ any chosen Amplitude, which is the same for all pulses and has a duration of t ^ - t ^. The Eechteckwelle 74- is a measure for the Duration of the particle pulse at a partial value of the amplitude of the particle pulse, which is one half in this EaIl. This Impulse is referred to in the following as the impulse duration measuring impulse, since the impulse enables the derivation of an electrical quantity, its Value is proportional to its duration.

.In the sensor 14- the pulse duration measuring pulse 74- is applied to the integrator 72 in order to generate the wave 76 of the graphic representation F. Since the pulse duration measuring pulse 74- from the comparator 62 always has the same amplitude, the slope of the integrator output is always the same. The increase in the output signal is in any case proportional to the duration of the pulse duration measuring pulse 74- which appears at the output of the comparator. It is recalled that the pulse 74- equals the pulse duration; of the original particle momentum 30 at a partial value of _; whose height is. In this way, the integrator 72 has converted the pulse duration measuring pulse 74- into an electrical quantity which has the pulse 76 which has a value, in this case an amplitude, which is proportional to the duration of the pulse duration measuring pulse 74- is. This output pulse 76 has as a profile a rise and a plateau, but it does not have to have the flat upper; f part as long as its amplitude is proportional to the duration ■ of the pulse 74-. The output pulse 76 of the integrator 72 ·; occurs on a line 78 and is applied to two _threshold: where 80 and 82 circuits. The purpose of these threshold circuits is to enable the circuit to select the desired and undesired pulses. |

Although it is desirable to use the particle derived impulses with the shortest pulse duration, since these pulses are those caused by particles that axially

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ΖΊ53Ί23

len or near-axial spans "when moving through the opening Follow it can also, be desired, the passage of "certain impulses, the speed of which is extraordinarily high is to prevent, for example, faster noise pulses. These noise pulses can be caused by many outside sources v / ground, for example through electrical connections outside the device, through earth currents due to the switching of high currents in other parts of the device, etc. As a result, the two threshold circuits allow two limits to be set or a "window" into which the integrated pulses must fall in order for the sensor 14 to emit an output pulse.

The upper level of the "window" is set with the aid of a reference voltage source 84 and a resistor 86 which is adjusted to provide a level 88 (graph F) at an input 90 of a comparator 92. The lower level of the "window" is set by the reference voltage source 84 \ and a resistor 94 which is adjusted so that he 96 (graph F) at the input [98 a comparator manages the level 100th Comparators 92 and 100 have output signals only when the input signals from line 78 exceed their respective input levels 88 and 96! From an examination of the graphic representation F 1 it can be seen that, while the pulse 76 rises, its edge exceeds the level 96 at the time t 1, so that an output signal on a line 102 has a certain duration. \ ! appears as described shortly. This pulse ends' at the time _t and the square wave 104 of the graph K. At the output line 106 of the comparator | 92 no output signal appears as the pulse 76 in ^none:; 'Place exceeds level 88. ^:

When the delayed pulse 66 falls below its half amplitude, as it is determined by the plateau of the pulse 64, the trailing edge of the output pulse 74 of the comparator in the

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. Trailing edge detector 108 is detected to provide a peak pulse 110 (graph E) at the input of a univibrator 112. It can be seen that the univibrator 112 is _{triggered at the time t r} and generates an evaluation pulse 114 (graphic representation G) with a predetermined duration. This time period is chosen to ensure that the following circuits have sufficient time to measure the eventual output pulse. This period of time can be from one to a few microseconds. The time period selected in the illustration goes from t 1 to t g and therefore the pulse 114 is a square wave of this duration, which occurs on line 116 and at the same time to a trailing edge detector 118, a veto, UlTD gate 120 and to a Trailing edge detector I22 is applied,

The duration of the evaluation pulse 114 controls the duration of the pulses 56, 64 and 76 through the trailing edge detector 122. The output signal of the latter on a line 124 is the differentiated peak 126 in the graphic representation H, which triggers another univibrator 128 to generate a reset pulse 130 (graph I) of any duration, for example from tr to tn, which short-circuits the pulse stretcher 50 and the integrator 72 through a line 132 until their storage capacities are completely discharged. This makes the circuit ready for the next; ■

jimpuls offset,
j

^: As the upper level was 88 not exceeded by the pulse 76 *, no output appears at the comparator 92 on the "· Line 106 There is no pulse for a Vorderflanken-- \ detector 134 occurred to which it would appeal. can.! also, on a line 136 a signal RS flip-plop has occurred to ^a! adjust 138th Similarly, no output signal occurred on line 140 at the veto input of the veto UITD gate 120. From the Lower threshold circuit 98 on line 102 and from univibrator 112

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there were output signals on line 116. Consequently, AND gate 12O provides an output on path 14-2 starting with a precision electronic switch or gate 144 activated. Of the. Output connection 16 is now connected to pulse stretcher 50 via line 54- during the duration of the pulse connected on path 142, which., of course the duration of the 'pulse 114 from the evaluation univibrator 112 is. The output signal on output terminal 116 then becomes pulse 146 fe of the graph N, which has an amplitude X and a Has a duration from t, - to tg. All impulses from the sensor 14

- are passed on have the same duration.

The particle Y is now considered, which is located far outside; of the axial center through the opening 22 has moved. Since it '■ is outside the axis of the opening, it is likely · ilich that the tip of the corresponding at the leading edge! , Impulse is an incorrect criterion for the particle size (volume) ι. The Volimen of the particle Y is, with the greatest probability proportional to the amplitude at about the middle of the ^im-: since this amplitude has been generated by the generation of the pulse • 'in the middle of the opening along its length ipulses · 34 ,; where the current density is likely to be most uniform. Instead of measuring idies, however, it is desirable to measure this momentum apart from [ j ■ · ■ i

! Take care and filter it out so that it does not have an output signal ■; nal generated that in the study just carried out the partial! size would have to be taken into account. i

1. . ■■ '■. 1

jThe pulse 34 is applied to the connection 12 and from there to the pulse

50 / i

j expander and delay line 52 is applied. The Fühlerschal-: | tung performs the same operations, described above in connection '■ - have been described with the pulse 30, and therefore the corresponding waveforms generated in the circuit, which, however, due to the greater amplitude and duration of the pulse 34 .. differentiate. The stretched pulse 148 has an amplitude Y.

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2113123

When compared with the delayed pulse 152 (graphic representation 0), the height pulse 150 now leads to a pulse duration measuring pulse 154 which has a much longer duration than the pulse 74-. This pulse 154 lasts from the point in time tq Ms to the point in time t 1, which is considerably longer than the time from t'-z to tr. When integrated, this pulse 154 produces a much larger pulse 156, the leading edge of which has the same slope as pulse 76. Because it lasts longer, the pulse 156 rises considerably higher than the pulse 76. When the lower threshold value 96 is exceeded, an output signal: is generated on the line 102, which is the pulse 158 in this case. In this case, however, the upper threshold value 88 is also exceeded _? and this creates conditions different from those obtained in connection with the ^: pulse 30.

Since the signal at 78 exceeds the upper threshold, there is an output on line 106 from the time t ^ Q at which this occurs, represented by pulse 160 in graph J. The leading edge- ! - detector 134 generates a peak 162. (graph _L); 'which occurs on line 132 and the BS flip-flop 138 sets, so that an output signal is generated on line 140 164 Since this is a veto signal. is, it prevents the gate any signal passes;!.! occurs as a result, although ider evaluation system univibrator 112 operates, and a signal on the Leiitung 102 is present, no output signalr ⁶ * 42. in this manner, the signal 34 discarded and never appears on that

! Output port 16. ".

: The pulses 166, 167, 168 and 169 are generated in the same way like the pulses 110, 114, 126 and I30. In addition, the trailing edge of the evaluation pulse 167 of the univibrator the back flank detector 118 scanned to detect a tip (not shown) which resets the RS flip-flop 138 to it

20982 0/0912 ". '"

to get ready for the next big impulse.

From the foregoing description it is clear that the sensor.

14 is built in analog design. The output of the comparator .62 is a pulse duration measuring pulse 74- which is sent to the integrator 72;

is applied, which converts the same into an electrical time signal 'pulse, which in this case is the pulse 76 with the flat ι upper section. This is the pulse that is compared to the two "'voltage levels 88 and 96 to determine whether" i the gate 144- is operating to allow electrical signals to pass through to the "output terminal 16. The evaluation pulse 11.4- on \ ider line 116 enters into the main part of the stretched pulse ι: 56 and extracts a portion of this pulse as an output of:

! ί

j probe. It is therefore a newly built and derived pulse ₍ 146 of a predetermined duration, which is determined by the characteristics of the university!

j vibrators 112 and an amplitude equal to the ampli- [ Jew X is. This is also the amplitude of the pulse 30.; ■

I j

Instead of integrating the pulse duration measuring pulse 74-, it could also be used to ensure that the pulses from a continuously running clock oscillator pass through in the manner of a gate . control in order to let a certain number of clock pulses through which is proportional to the duration of the pulse duration measuring pulse 74- This number of pulses can then be counted and the counter | ! stand can be compared with a predetermined number, the "i, the upper limit of clock pulses representing the maximum of partial chenimpulsen still acceptable desired as is, if the number of pulses transmitted through the measuring ^pulse. be , is greater than the upper limit j previously set in the counter, then the operation of the gate is blocked and the evaluation pulse 114- has no effect

I i

'than the upper limit, the evaluation pulse can pass the gate for a long time' ^! enough operate to produce an output signal 146 which is derived from, the stretched pulse 56, which in turn is derived from the \ iTeilchenimpuls 30th So is the arrangement of the im

209820/0912 "

following described digital sensor 14 in which the counter up to a -predetermined number by the clock pulses -'count or returned to zero from a predetermined number

can
to create an output signal. _:

The digital sensor 14 is shown in FIG. All parts preceding the comparator 62 are the same as in FIG. The integrator 72 is replaced by a digital counter 172. ^The: circuit blocks 108, 112, 120, 122 and 128 have the same .Funk- \ tiön as the similarly numbered blocks in Figure 4. Some formwork ^l · 'processing blocks are added, namely, a clock oscillator 174, · an OR gate 176 having a plurality of inputs and a switch 178 with I preset. If a particle-generated impulse is sent to the | 'Input terminal 12 is applied, it is stretched by the pulse stretcher .50, attenuated by the attenuator 58 and delayed by the i' signal delay line 52. The duration of the pulse on the line 70 is, as before, a measure of the height portion of the pulse width. Clock pulses are ^ to an AND gate 180; continuously given on line 182 "When a pulse or [• a logic 1 is present on the road 70 clock pulses may occur on the way 184 of! the oscillator 174, since, as will be bejschrieben which vorheseingestellte, down-counting counter i ■ 'i

172 outputs signals corresponding to the logical 1 to one or more j of the inputs of the OR gate 176. If so, path 186 also has a logical '1. Under these conditions, the clock pulses cause the counter to count down towards zero. When "good" pulses to be adopted, however, the counter is set to a higher number of clock pulses before when arriving during a Ausgangsim- '\ pulses from the comparator 62nd A signal corresponding to logic 1 therefore remains on the way if zero is not reached, and if the evaluation univibrator 112 is triggered by the back edge of the pulse from the comparator 62, the evaluation output pulse occurs the V / eg 116 through an AND gate 120 to generate a control pulse via the V / eg 142

209820/0912

- ■ '■■' // '- ■■'

to apply, which turns on the gate 144 and the pulse stretcher 50 as described above, controls, with the output terminal 16 a pulse is reconstructed which is the amplitude of the original Particle pulse and the duration of the univibrator 112 has. The reset vibrator emits on the trailing edge of the evaluation pulse 128 a pulse on the path 132 from which resets the pulse stretcher and causes the switch 178 to open the counter 172 sets the predetermined, desired maximum-n count.

'Venn is the counter to this Weise.voreingestellt appears "I, a logic 1 on the road 186 in preparation for the next'^•; pulse from the comparator 62nd

Let us now consider what happens when a particle pulse is applied to terminal 12 which, measured at the desired partial value level, is longer than desired. The comparator 62 j outputs an output signal 70 as before and therefore enables ^; that clock pulses from the oscillator 1-4 on the line 182 through S the AND gate 180 on the path 184 are given. The clock pulses j cause the counter to count down towards zero. If j _; if it reaches zero, all input signals are sent to the multiple input of the ÖDER gate. 176 is removed and the output signal on the path .186 changes to a logical 0. This means that every; Another clock pulse is prevented from passing through the AND gate 180 and a logic 0 is applied to the upper input j186 of the AND gate 120 at the same time. The logic 0 at the upper input prevents the evaluation pulse from being applied to gate 144 via paths 116 and 142. Therefore, no output signal appears at the connection 16. On the trailing edge of the evaluation pulse ε, the univibrator 128 resets the pulse stretcher 50 and sets the counter 172 again, as described above.

20982Q / 0912

ί f.

Those in the B ¹ Ig.? The probes 14 shown in FIG. 9 and FIG. 9 for particles having an axial path are also characterized by means for distinguishing between pulses of different pulse durations, on the basis of which the desired pulses are selected and passed through the device. This pulse selection is automatically controlled and activated by the pulses themselves. operates on the assumption that virtually all of the desired pulses will have the same duration, and that this duration is the maximum allowed duration. All pulses whose pulse duration exceeds this maximum are therefore blocked or discarded, and 'all pulses which are shorter than the maximum duration '. ■ have are accepted. A pulse duration tolerance is in the; Circuit provided so that pulses whose pulse durations are slightly greater than the maximum are accepted »?

In addition, it is provided in these exemplary embodiments that the sensor is switched off while a pulse is being processed is to prevent partial pulses with very small pulse-j duration of an undesirable long-term reaction in the discriminator cause, for example, if the Device too soon after processing a pulse to-Ί is ready to accept and an immediately following particle pulse is accepted is after a part has already been withheld; is. Simple threshold value devices can be used to prevent noise signals from being connected to the discriminator. prevent. . "

In the embodiment shown in Fig. 9, the output pulses are actually reproductions of the input pulses achieved by the delay circuit rather than a f Reconstruction of the pulse input signal as in the exemplary embodiments according to FIGS. 4, 6 and 7

In the following, reference is made to Figures 7 and 8 (in which the new parts begin with the reference number 200 and the elements that correspond to the elements shown in FIGS. 3-6. speak, have reference numbers below 200). To the input port

209820/0912

12, a pulse train is applied which comes from the analyzer 10 described above.

First, the pulse 30 is considered. He has an amplitude of X and appears on the assumption that it is passed by a gate 200 ^N is applied on the Leitung202 and is simultaneously applied to the pulse stretcher 50 and the signal-delay member 52nd The capacitor of the pulse stretcher 50 follows the leading edge of the pulse 30, charges up to the amplitude X and holds this charge after the fall of the pulse 30. The result is a pulse 56 with a flat top (graphic representation B from 3? ig.8), the. has an amplitude X and a duration which is controlled by other parts of the sensor. = This pulse occurs on the channel 54 for transmission to the attenuator 58. _: ; and output gate 144, the latter at the time j

^ point is closed at which the pulse 56 begins. The attenuator 58 attenuates the pulse 56 to a desired partial ■! value of the amplitude X, and the resulting, partial: 'amplitude pulse 64 of the graphic representation C appears on the input line 60 of the comparator 62. In the meantime, the pulse 30 has been delayed by the signal delay line 52 and occurs as a pulse 66 on the line 68, which forms the second input to the comparator 62 * The partial amplitude for the pulse 64 is selected so that a clear comparison with the pulse 66 can be made. This vert can preferably be 50 % , but other partial values can also be used.

The two pulses 64 and 66 are shown one above the other in the graphic representation G of FIG. Where the impulse 66 exceeds its own partial height measured by the damped impulse 64, ie between the time t ^ and t ₂ , the comparison has ^! rather 62 an output on line 70 which appears as the square pulse 74 shown in graph D "This is the input to a veto AND gate 204. It is also an input" to the trailing edge detector 108. The output the-

2Q9820 / 0912

This detector has the tip 110 of the graphic representation F on, from the time t ^ through the duration of the pulse 74 is separated up to the point in time tp and which is connected to an a ^ - passage of a veto UHD gate. 206 is applied and which, when the gate is open, passes to a univibrator 112 which is arranged at the input of a time sequence generator 208 to generate a rectangular output pulse 210 (graphic representation G) to be generated between the times tp and t. In in the same manner, as will be described below, the clock pulses 212 and 214 are generated at the times indicated in the graphs I and K are shown. Tips 216 and 218 of graphs H and J. are indicated by the respective trailing edge detectors 118 and 122 are generated. The tip 216 triggers another univibrator 220 while. tip 218 triggers univibrator 128. The clock pulse 212 occurs on lines 116, 222, 224, 226, 228, 230, and 232.

When the clock pulse 212 occurs on line 230 to the veto input of the veto AND gate 204, this closes the gate. Note, however, that this occurs during the period from t to tr the pulse duration measurement signal 74 at the time from t- to tp occurs through the gate 204 and appears on its output line 234 and becomes! applied to the integrator 72. The integrator 72 integrates this; Comparator output signal 74 and generates a pulse 76 ^with ! a rise and a plateau., where. '. the plateau of the j Zeitpurifc to "when the comparator signal drops to the ■:. takes tr-" The time it Ze sequence generator 208 j end of the comparator output pulse 74 is at the \ energized and maintains all.!

! ■ j

further incoming signals until the measuring cycle is completed, as will be explained below.

It should be noted that the output clock pulse 214 of the univibrator 128 at the time tr (graph £)

209820/0912

begins and extends to a desired point in time, for example tg. It is applied to the pulse stretcher 50, the short-circuit input of the integrator 62 and a logic control circuit 238 via the lines 132 and 236. The pulse stretcher and the integrator are reset in this way by the signal 214 between times t 1 - and t 1 -. '■

The univibrator 220 is the evaluation univibrator of the sensor 14 and its output pulse 212 prevents further trigger spikes coming through the veto AND gates 206 and 204, and also opens the AND gates 240 and. 120. The effect of this will be briefly described. If this evaluation pulse 212 can pass through the AND gate 120, it becomes the pulse 114: (graphic representation N) on the line 142 and opens the | '- .. gate 144 between times t, and t, - and can be characterized ^for a portion of the pulse 56 to pass through to the terminal 16th The ₍ resulting output pulse 146 (graphic representation 0) has the amplitude X and the duration from t1 to tj- ^.:

¹ Whether the evaluation pulse is effective or not depends on a memory circuit 242 for a minimum duration, which represents the discriminator in order to determine whether the evaluation pulse J is passed on. ·

The integrated signal pulse 76 appears on line 78 and - - I is applied to a comparator 244 and also to a line 246 j puts which one input to a comparator 248 in memory circuit 242 for the minimum period of time. The output j of this circuit 242 occurs at 250. This exit points j has a DC voltage which is proportional to the desired: minimum period of time. This tension is called the lower of shown by the two broken line waveforms of graph E and designated 252. The memory circuit controls whether the pulse output 76 from the integrator 72 acts to pass a portion of the stretched pulse 56 through

209820/0912

the output gate 144 of the channel to the output terminal 16 lets pass. If.the amplitude of the integrated pulse. 76 exceeds the voltage level 252 by an amount that is determined by the gain of an adjustable gain amplifier 254 with the upper level being controlled by the upper one of the broken line waveforms of the graph E of Fig. 8 is shown in particular at 256, then the Output gate 244 closed so that no signal to the output can penetrate output terminal 16. This situation is illustrated with reference to the integrated pulse 156 generated by . the undesired pulse 34 is derived. '

The memory circuit 242 has an input comparator 248 ' which feeds one connection of the AND gate 240, the output line 258 of which is connected to the short-circuit input of an integrator 260 * lies. A constant current source 262, for example a j

Constant voltage source and a fixed resistor has one

will/ . ^!

Output each is applied to integrator 260 to cause

• the voltage at its output 250 increases very slowly, see above that the supplied constant current Any leakage current on the Input of the integrator exceeds to ensure that the integrator always has the tendency to drift upwards and never has to drift down

The pulse 212 from the univibrator 220 provides an input to the AND gate 240 on line 224 after the integrator pulse 76 has stopped rising. If at that time the voltage on line 246 is less than the feedback voltage on line 264 from integrator 260 to comparator 248, the comparator has an output which is gated with the signal on line 224 to to produce an output on line 248 shown as pulse 266 in graph L. If this occurs, the discharge section of the integrator 260 is energized,

209820/0912

Γ "

. . ■ - 30 -

so that the voltage on output 250 at time t- is caused to occur, as shown in graph E * When the feedback voltage on line 274- falls below the voltage on line 246 at time t ^ falls, the output of comparator 248 removes the chart signal 266 from AND gate 240 ₁ causing the integrator output to remain at a new value that is the same value as the output from integrator 72 on line 246.

If the value on line 246 has an amplitude greater than the voltage on the line 264, as it is with the pulse 156 of the EaIl, the comparator 246 has no control output, the short circuit portion of integrator 260 is not actuated and the output voltage at 250 is not affected. Since only pulses with pulse durations that are shorter than the minimum mentioned, the drop in the integrator output occurs In this way, the output voltage at 250 becomes proportional to the duration of the previous shortest pulse and a measure of that duration. This will give a maximum duration set. - - - - -

The voltage derived and occurring at 250 is applied to the Amplifier 254 with adjustable gain applied, the one Has gain slightly greater than 1. This allows pulses that are slightly longer than the set maximum , represented by level 254, from the sensor 14 are accepted and passed on to the output terminal 116. This is achieved by the fact that the time-linked Pulses that occur on path 78 with the DC voltage compared to those at the output signal 268 of the amplifier occurs. If a pulse is longer than a certain small percentage longer than the duration of the previous minimum duration pulse it exceeds the voltage at 268 when the gain of amplifier 254 is set so that

209820/0912

- 31 -

that it exceeds the factor 1 by this small percentage. Only pulses of shorter duration therefore result in an output signal on line 140, which is passed on to AND gate 120 will. - ".

In this case, the setting of amplifier 254 is a manually operable adjustment element 270 for the gain factor achieved. The voltage level on line 268 corresponds to the waveform shown in broken lines 256 of the graphic representation E of FIG. 8.

Since the voltage plateau of the integrated pulse 76, which is derived from the desired pulse 30, does not exceed that on path 268, nothing happens on output path 140 _(of the comparator, as shown in graph M and as can be seen is, it is a positive level, which means that the comparator 244 normally has an output which is switched to a logic 0 if the voltage at its upper input 78 ^{exceeds that of the lower input!} 278. The occurrence of the evaluation pulse 220 effected on the 'path 116 to Auswertimpuls 114, so that thereby the output j to the STATEMENTS 16 with the channel during 54- i on line 142 |! the duration of the associated Auswertimpulses It follows j.

each output pulse 146..

i -.

(If an undesired pulse occurs, for example! The pulse 34- * runs through almost the same sequence of steps. The pulses and waveforms 148, 150, 152, 154, 156, | 280, 282, 284, 272, 286 and 28 ^, ^e2 o ^? xe ¹ ^ perspective are shown on the right 'of Fig. 8 in the graphs B, C, D, D, E, F, G, H, I, J, K and M. When the rise of pulse 156 exceeds voltage level 256, comparator 244 toggles and removes a gating output from path 140. This is shown as the negative pulse 164, shown in graph M, beginning at time tg.

209820/0912

Since it has only one input signal, AND gate 120 ignores the gating pulse 212 on line 116. Hence has the control line 142 does not have a pulse that corresponds to the control pulse 114 corresponds, and the amplitude Y of the long-term particle pulse 34- is blocked and discarded. Apparently it is then too there is no output signal at terminal 16.

Similarly, the voltage on path 78 exceeds that

is applied to the input of the comparator 248, which is on the path 264, as shown in the graphic representation E, starting at the time t ^ v. The UHD gate 240 therefore has no control input signal when the evaluation pulse 272 is applied at the time t ^ _Q. The short circuit portion of the integrator 260 is n * deenergized and the voltages on paths 250 and 268 remain unchanged. The minimum duration circuit 242 therefore continues to store the voltage corresponding to the shortest pulse. There is therefore no pulse equivalent to pulse 266 (graph L).

A port 274 is between input port 12 and the pulse stretcher 50 used. If this gate is not open, you can no signals of any kind are picked up by the sensor 14. The mode of operation of this gate is determined by the logical Control circuit 238 controlled via its output line 276. this ™, in turn, has the function of making the sensor ineffective for so long. like any signals on one of the lines 278, 279 »232! or 236 are present. Setting the delays that | ! generated by the time sequence generator 208 enables the [Setting the time during which the sensor is switched off! on the processing of an impulse, which prevents ! that any signals are recorded prior to processing of a previous signal is complete. The logic circuit 238 also prevents signals from triggering the probe. This is achieved in that the voltage level at the input terminal is monitored in the logic control circuit the line 278 is fed and the gate 274 is held blocked until the input 12 is free.

209820/0912

The feeler 14 ·, <fe? in connection with FIGS. 9 and 10 has been, differs from the sensor 14 from Fig.7 "in a relationship that causes a significant change in the nature of the output signal generated. In the case of the probe of Fig. 7, the output at 16 is a square pulse the amplitude of the particle pulse generating it and the duration of the output pulse generated by the univibrator 220. In the case of the sensor shown in Fig. 9 for particles with an axial path, the output signal is a delayed version of the original pulse, this being achieved through the use of a double delay arrangement. The duration of the univibrator evaluation pulse from the, univibrator 220 is long enough to allow all delayed particle pulses to pass. There is also a slight difference in the Timing of the circuit.

Instead of showing the entire modified sensor, FIG. 9 only shows the modifications, the part not shown being designed in the same way as in FIG. 7, which would just be described.

The only new element in FIG. 9 is a second delay line 290 which is coupled to the output of the first-mentioned delay line 52 via a line 292. The output of the second delay line 290 opens into the channel 5 ² S while the output of the pulse stretcher 50 is no longer coupled to the channel 54. The only other modification in FIG. 9 is a modification of the trailing edge detector 108 of FIG. 7j in such a way that it acts as a leading edge detector 108 '. '<

Because the sensors according to FIGS. 7 and 9 are essentially the same, are also only minor differences between the resulting Waveforms and pulses shown in Fig. 8, as well as the circuit parts that could have been shown in Fig. 10, available. In order to avoid repetition, only a part of these waveforms is shown in Fig. 10, the ones not being shown in the graphs B-E with the waveforms shown

209820/0912

- 34- of Fig. 8 are comparable.

So that the impression does not arise that the shapes of the particle impulses 30 and 34- are subject to a restriction, FIG. 10 shows the desired impulse 30 'and the undesired impulse 34-' with a shape which is somewhat modified from the impulses shown in FIG. The duration of the desired pulse 30 'extends from t * "to to and the duration of the undesired pulse 34-' extends from tq to .... These pulses are delayed by the delay element 52 so that they are at times t ^ and t ^ or t ^ ₀ and t ^ lie.

The particle ^{pulses 3D 1} and 34 'are stretched, decelerated, attenuated and compared by the elements 50, 52, 58 and 62, as was described above with reference to FIGS. 7 and 8.

They are delayed a second time by the delay element 290 and appear as pulses 294 and 296 (graphic representation L of Fig. 10) at the time int intervals tp- to t ^ and

; t ₁₄ to t ₁₅ . :

! Each time the comparator 62 receives a pulse on the

Line 70 generated, the time sequence generator 208 generates © inen j clock pulse train, these pulses being the pulses 210 (graphic j diagram G), 212 (diagram H) and 214- (diagram see Representation I) are. The leading edge detector 208 receives the comparator output and generates the peak 210 ι (graphic representation F) at the time t ~. If those Tip passes through the veto AND gate 206, it triggers the univibrator 206.

It will be recalled that element 108 of that shown in FIG Sensor was a trailing edge detector. To reduce the clock cycle to a minimum, it was only necessary that the sawtooth pulse reaches its final value before the evaluation multivibrator is triggered reached. The leading edge of pulse 210

209820/0912

is used in the case of the sensor of Fig. 9 to effect that the evaluation pulse 212 is simultaneous with the double-delayed Particle pulse 294- occurs.

The time sequence generator 208, the control logic circuit 238 and memory circuit 242 operate for the minimum duration as described above. The output of the AND gate 240 in the memory circuit generates the pulse 266 (graphic Representation K of Pig. 10) between times t, - to t, -.

Assuming gate 274 is open, reasonably short pulses of particles from input port 12 will travel through signal delay lines 52 and 290 and appear as pulse 294 in channel "54, as shown in graph L, without changing the waveform. Whether or not the output gate 144 enables these particle impulses to be applied to the output terminal 16 is determined by the state of the logic signal appearing on the control line 142 from the AND gate 120, this being the output signal 298 is shown in the graph of "Figure 10 This in turn depends on whether the ^import;... pulse width exceeds or does not exceed, which is by a predetermined percentage amount greater than the duration of the previous minimum duration pulse, the the latter is carried out by memory circuit 242. The percentage margin is determined by amplifier 254 and its gain setting lung '. 270 set. When output gate 144 conducts, the j delayed particle pulse 300 occurs, shown in the graph

ment N is shown at the output terminal 16 on. j

'ί

The purpose of the time sequence generator 208 is to generate a clock sequence which is triggered at the moment when the j particle pulse is delayed and applied to the comparator 62 exceeds the partial height determined by the attenuator 58. This point in time is shown in the graphs of FIG. 10 the time t 1. The univibrator 112 becomes like this

209820/0912

set it to be slightly less than the total delay of the second delay line 290 so that the complete particle pulse appears at the output terminal 16. The pulse duration of the univibrator 220 is correspondingly somewhat longer in time than the longest acceptable or desired particle pulse is likely.

It can be seen that the output of logic control circuit 238 controls whether or not a particle signal is accepted not. During the period in which the signal 30 'at the

■ circuit, ie 12 appears between the times t ^ and t ~ this logical control circuit generates a 0'gezeigtes in the graph of signal 302, which permits recording by the sensor fourteenth At all other times the ^: particle signals are not accepted.

ι i

Let us now consider impulse 34 ', which evidently has a time

• has duration from tq to t ^ which is considerably greater than the duration

of the pulse is 30 '. The processing of this impulse goes '. ' in a manner similar to that which was described in connection with ' j the pulse 30 ', and also as that which was described under: with reference to the pulse 34 of FIG. Therefore the pulses 304, 306, 308, 310, 312 and 314, which are shown in Fig. 10

■ shown in graphs F, G, H, I, J and 0; are generated as shown. It can be seen that there is no pulse equivalent to pulse 266 that would have occurred at time \ t ^ -y because the integrated pulse is greater than j the feedback voltage in memory circuit 242. j Therefore, its gate 240 remains closed and no pulse equivalent to pulse 298 (graph M) occurs, j so that pulse J4 ^{1 is} rejected. ;

In the exemplary embodiments already described, sensors and methods for scanning such particles with a described the axial course of the path in order to avoid the undesired particle

209820/0912

impulses due to their long impulse duration. The following device and the described with reference to Fig related methods solve another problem that has not been mentioned before. Although many particles passed through the Passing through the opening, entering off-center and even close to a corner, they then move to the axial Center and finally exit near the center. This type of particle generates an impulse, the duration of which is almost is the same as the duration of the pulses generated by the particles previously designated as "desired" that ■ pass through the center. Therefore, such an impulse is not rejected by the embodiments of the sensor, whether- ' probably he a peak or an overshoot, usually at that Leading edge may have whose amplitude is not a correct one. ; Hatred for the size of the particle is. It is reminded that in the axially central region of the opening the electric field of the "opening is most uniform, and if a Particle passing through this area is its amplitude! in the best approximation proportional to the size of the generating it Particle.

The embodiment shown in FIG. 11 provides a method and a sensor to find the central region of the pulse on which has an amplitude which is lower than every j peak on the leading edge or the trailing edge. The central j amplitude information is used to derive an output pulse I, the amplitude of which is well proportional to the magnitude \ of the particle, which has generated the particle momentum.

In other words, the method and the circuit for scanning the particle sizes in accordance with the exemplary embodiment shown in FIG. 11 provide an output signal proportional to the volume of the generating particle at the point in time where the particle is halfway through the

209820/0912

2Ϊ53123

Opening is located v / o the electric field is most uniform. The point halfway is the optimal location of the particle in the axial direction. Therefore, the circuit of this exemplary embodiment only detects those particles which pass through paths which are optimal with respect to the radial direction and scans these particles at their axially optimal positions. ^:

It can be seen from FIGS. 2, 3 * and the graphic representation A of FIG. 12 that if the particle Y of FIG. 2 were to change the last section of its trajectory 26 so that it runs closer to the axis As shown by the dashed path 326, the result would be the pulse 334- shown on the right-hand side of graph A of FIG. The peaks 36 and 336 of FIGS. 3 and 12 would have the amplitude Y as shown. The amplitude Y ¹ in the middle of both pulses 34 and 334 would also be the same, since these values represent the measurement of the particle Y when it is related ^! borrowed the opening is in the same position, ie in the middle of the j axis. Of course, the pulse 334 · neither the top: at the trailing edge or the unwanted pulse duration of the pulse 34-, shown in Figure 3, as his long path section of the axis of the opening is 326 corresponds \. Indeed, from t ^ to ty, ^ of pulse 334- the pulse duration becomes very similar to the duration ty. to tz of pulse 30, as shown in graph A of FIG. Hence, pulse 334- represents a "wanted" pulse.

Since it is assumed that the particle Z has the path 28 (Fig.2); its duration (Fig.3) is too long and such an impulse becomes j

I- j

from the embodiment of the sensor shown in Fig.11 ver-j threw. ;

: Before the circuit details of the embodiment shown in FIG As a general rule, it should be noted that, with the exception of the improvement in locating the pulse center the sensor of Fig. 7 with its input and output elements,

209820/0912

the logic control circuit 238, the time sequence generator 208, the memory circuit 242 for the minimum duration as well as with the Expansion circuit, the attenuator, the comparator, the evaluation and veto circuit described in detail above. Because of this arrangement of common elements, the description limited to the bare essentials with reference to FIGS. 11 and 12.

Consider now the processing of pulse 30 shown in graph A of FIG. It appears at input terminal 12 and is applied via line 278 to control logic circuit 238 which has a low threshold level 338 to prevent noise signals from actuating the sensor. During the time t. - t ^, in which the pulse 30 exceeds the lower threshold level 338, an output signal occurs on the path 34-0, which can be regarded as a logical 1 and is represented by the square-wave signal 342 in the graphic representation B. The signal 3 ^ 2 is differentiated and rectified by a leading edge detector 3 ^ ₅ to = generate a short trigger pulse 3 ^ 7 at time t * on path 348, as shown in graph G. This trigger pulse 346 is used to set an RS flip-flop 350, which in turn applies a control input signal .352 to a gate 354. The control input signal 352 is \

a square wave between times t ,, and tp, as in . the graph D is shown and its duration is i controlled by the device that the flip-flop 350 back-; , sets, as will be described later. The logic control circuit; 238 switches gate 274 via the control,

; line 276, so that the particle pulses appearing at the input j connection 12 pass through to the connection 202 and from there to the signal delay element 52, while at the same time they pass through the gate 354 to an integrator 356 ^: step.

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When gates 274 and 354- are both open, integrator 356 begins to accumulate charge, its storage rate depending on the size of the particle and its pulse 30. An amplitude adjustment element 358 is connected to the output terminal of the integrator 356 and has been previously adjusted so that when a particle is halfway through the aperture, the voltage on input line 360 to a comparator 362 is equal to the amplitude of the original particle pulse 30W which also arrives at the comparator 362 via its other input path 364- which leads via a hold circuit 366 which is connected to the output of the gate 354-. At this point in time, the voltage on path 360 increases steadily, while the voltage on path 364- is momentarily constant and represents a particle that passes through the location with a uniform current density in the middle of the opening between its ends. ^! . - ι

The amplitude setting element 358 can operate automatically or can be set manually to a certain characteristic which changes the scale of the output of the integrator 356 in order to _; to achieve the desired results. The automatic Amplitudeneinstellelement is a commercially available component '; which can be modified to the desired function durchzu-j jführen. It can be an analog multiplier such as that sold by Motorola, Inc. under catalog no. MG 1595 L, sold j; which is then modified to work as a divider. ; : Detailed instructions for. these amendments are indicated in 'The Micro-elektronics Data Book, 2nd Edition- published by the; ! is published.

I ■ ■

It will be recalled that the DC voltage is applied to the output terminal 250 of the memory circuit 24-2 for the minimum duration is proportional to the duration of the shortest particle pulse given by the probe 14. This tension is over a

209820/0912

Feedback line 368 for setting the operating mode of the automatic amplitude adjustment element 356 is used by that the input voltage of the integrator 356 by the Feedback voltage line 368 is shared. Because of this automatic arrangement and this circuit, know the size the opening and the flow velocity can be changed, • to make the pulse lengths of the resulting particle pulses different. The resulting. Input voltages on the However, comparators cause the integrated value to be equal to the held value at the. Center of the impulse duration of the Im-. pulses is 30 as requested above.

I If the voltages on the paths 364 and 360 become the same at the time ■ t2, the state changes at the output of the comparator ι 362, and the signal pulse 370 is generated, which is shown in the graph F. j

Graph E illustrates what has just been described. The signal appearing on the path 364 is essentially the same as the partial pulse 30 and is therefore labeled 30. The set output of the divider 358, which appears at 360, is represented by the rising waveform 372. The point at which the two voltages are equal to j occurs at the point tg and is at 374 · Marked 30 at the top of the pulse. At this point, the pre-matcher 362 produces its output signal 370 which is applied to the "Vbrderflankondefcefctor 374" to produce a trigger pulse j 376 shown in graph G of FIG. 378 is applied to the Jtüeksetze input of the BS flip-flop 350, so that it resets the flip-flop and ends the corner wave 352 of the graphic representation at time tg. The gate 354 is then closed, the integrator 356 has its integrating function at this time completed and holds his

- ORJGfNALiNSPECTEP

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Charge, so that its output signal is at a voltage level remains, which is the same as your maximum achieved value. This level of tension is equal to the amplitude X of the particle pulse 30, when the particle belonging to the pulse is halfway through the opening. The resulting waveform 380 (Graph E) is applied to the damper and hold circuit 58 which decreases its amplitude to a predetermined fraction of the original amplitude of waveform 380, so that the damped wave 382 (graph H) results which is at the input terminal 60 of the comparator 62 appears. In the meantime, the original particle pulse 30, pending at 202, has been sent to the signal delay element 52 is applied so that a delayed signal appears at the other input terminal 68 of the comparator 62. The delayed signal is shown at 384- on the graph H shown. The comparator 47 is the common type of differential amplifier, however, it is connected and arranged so that there is no output at 70 unless the voltage is on the input 68 exceeds the voltage at the input 60. Therefore, there is only a signal output if the pulse 384 the damped wave exceeds 382 and this occurs between times t ^ and tr. The output of the comparator 62 is the square pulse 386 (graph I of Figure 12).

The voltage at the output 70 of the integrator 62 is stored beyond the point in time tr until the sensor circuit _; 12 had plenty of time if the particle momentum was short enough to represent a particle at an acceptable axia- len trajectory to determine. This is carried out in a way as it was previously done in the embodiment shown in FIG ^. game was explained . It will be recalled that the wave form of the signal 380 ^l, which was passed through the channel 54 to the analog · ι gate 144, has an amplitude which is not equal to j, the amplitude of the original 30 is particle momentum, as at the sensors of the previously described embodiments was the case. Instead , its amplitude is equal to the amplitude that was reached by the original particle pulse, if the corresponding de. Particles on .. halfway through the public

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nation 22 found. So it happens that in the event of a desired one Pulse, "for example of pulse 30, the amplitude X of waveform 380 is the same as the amplitude X of the pulse is as shown by the amplitude X in the graph E. In the case of the pulse 334- this is the case but not, as will be briefly described.

The mode of operation of the remaining part of the sensor of Fig. 11 will be briefly referred to below with reference to particle momentum 30 and the main parts of the graph of FIG Fig. 12 described.

The integrator 72 generates the linear rise and the plateau of output pulse 388 at the input of comparator 244. The minimum duration memory circuit 242 takes one Voltage output at 250 from integrator 260, which is a Measure for the duration of the shortest pulse that comes through the sensor 14. This voltage output is interrupted by the Line 252 of graph M is shown. ; The upper broken line 256 gives a tolerance that

is set in the circuit with the aid of amplifier 254 ^,! that set by the gain setting element 270; will. If the amplitude of the pulse 388 does not exceed the level 256, the short pulse 266 from the comparator 248! is generated by AND gate 240 on line 258 j /. '!

; and used to short the integrator 260, where j

'■■ its output voltage level 256 to the same amplitude as that . of pulse 388 is brought to the linear slope and plateau. Characterized a slight drop in a wide ¹ rupted lines 252 and 256 is effected as between the time '■. points tg and t, -, is shown and in addition a new one _; The level against which the impulse is compared with the linear rise and the plateau.

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The univibrator 112 generates a corner wave 390 from the point in time tr through tg as shown in graph J. is. The trailing edge of this pulse is caused by the detector

© in

Sampled 118 so that trigger pulse occurs tg to the time point, to actuate the one-shot 220 to a square wave pulse 392 (graph K) between the times t ₆ and tg on lines 222, 224-, 226, 228, 230, 232 , and 116 which prevents the pulses from entering the probe 14 during the processing of a previous pulse. Partial pulses that are generated by a rapid auxiliary sequence of pulses cannot therefore affect the sensor.

The square pulse 392 is the evaluation pulse, which is the output of the sensor 14 controls. Its trailing edge causes a rectangular output pulse 394 (graph L) to appear ι the lines 132 and 396 occurs to the integrators 72 and j 356 to short-circuit at the time tg. The pulse 394 sets proceeds to a complete discharge up to the time t ^ Q of the capacitor of the integrator. ;

: The evaluation pulse 392 is applied to the UHD gate 120, and,: if a signal ah is present at the input 140 during this time period ™ I tg - tg, an open 'occurs during this time. j hold action to open gate 144- to cut out part of the \ j pulse 380 so that at the output terminal 16 ·! a pulse or signal 398 between times tg and t _g ! is generated whose amplitude is the same as that of the signal; 380 and its duration is always the same as the duration of the

vibrator 112 generated square pulse is. j

j i The pulse described next is pulse 334, which represents particle Y as it passes through the aperture 22 passes on the combined web 26, 326, which comes near the edge 40 at the entrance of the opening, after which «each

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but through the opening on an almost axial path. As a result, the characteristic overshoot 336 (graph A of FIG. 12) is generated on its leading edge. Of the However, the pulse has a short duration so that it is not discarded based on the pulse duration.

Now the same chronological sequence of events occurs. The pulse 334 exceeds the lower threshold value 338 between:, times t ^ and t ^ ₇ , and the logic control circuit 238 ■ therefore generates a signal 400 (graph B) between these times. The leading edge detector 244 generates a trigger pulse 402 (graph C) at time tJ to set the RS flip-flop 350 and thereby generates a square pulse 404 (graph D). The gate 354- ι

y y

is opened so that the pulse 334- by the integrator 356 ^; (runs and the integrator output follows the pulse shape 406 shown in graph E. This operation of the integrator is slightly faster than that for the pulse 30 because of the smaller area of the peaks 336 between the times t ** and t ^ o is somewhat shorter than the corresponding interval between the times t ^ and tp. Since the pulse 334 is quite flat near its center, this has very little influence on the Voltage at the point in time of equality. Therefore, the amplitude Y 'is, in a very good approximation, equal to I' of the amplitude X, although the maximum amplitudes of the two pulses 30 and 334 differ considerably

ι ■■ '■■■■'!

When the amplitude Y 'has been stored, the operating i

, the sensor 14 of FIG. 11 is the same as above in connection with j

related to the pulse 30 described. The-comparable VeI- j

lenforms are as shown; Pulses 408 through 426 are;

the equivalents of pulses 370, 376, 382, 384, 386, 390, 392, "

'394, 388 or 398.!

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The half-wave duration of the pulse 33 ^ is almost the same as that Half-height duration of the pulse 30. Therefore, the pulse duration measurement pulses 356 and 416 practically the same, and the pulses 388 and 424 with the linear rise and the plateau rise to almost the same amplitude. Since the pulse 424 the voltage level 252 on the path does not exceed 268 if accepted that the pulse 334- next after the pulse 30 is followed, the comparator does not change its state. Of the fc integrator 260 is not discharged and there is no pulse equivalent to pulse 266 from graph IT on. The minimum duration storage circuit 242 is only at level 256 based on the duration of the pulse duration measurement pulse 356 of pulse 30 is set.

: From the preceding explanation it can be seen that the _t part of the probe for finding the center point does not distinguish between particle pulses which correspond to an undesired pulse; have permanent value. Therefore the feeler must distinguish between the pulses of normal duration and those of greater than [normal duration regardless of whether they have false peaks. The part of the circuit for finding the * '■ center point is not as accurate in pulses of greater duration of the type 44 of Figure 2, and therefore it is best that these be discarded in any case. Therefore, the quality of the signals, for example the signals 398 and 426, which are generated at the output terminal 16 and which are derived from particle pulses belonging to particles with nearly axial trajectories through the opening, is much better than the quality of such output signals which would be obtained from a sensor that has only the pulse duration discriminator means or only the means to find the center.

ι The embodiments shown in Figures 13 and 15 of the Sensor for "particles with axial trajectories that are called

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are grounded described next v / concerning the problem of processing of pulses that are not well-defined ^front: flanks and have Kückflanken and the problem of filtering of pulses with multiple peaks. The multiple peaks indicate a pulse generated by a particle passing through two locations of high current density as it passes through the opening. Its amplitude is irregular and therefore not proportional to the size of the particle.

In the case of the particle pulses generated by the exemplary embodiment shown in FIG are measured, their pulse duration is from the first peak of the pulse to a partial amount of their Amplitude detected. The peak \ cLrd is detected by differentiating the particle momentum once and selecting the point at which the resulting signal passes. This means a slope equal to zero or a peak of the particle momentum. The resulting heat signal is then converted into a pulse, the amplitude of which is proportional to the duration of the Measurement signal is. This amplitude is then compared with a certain signal level to determine whether the original ■ particle momentum had such a size that it was height analyzer can be passed on or that it is discarded must become.

In the following, reference is made to FIGS. 13 and 14. The an- j ! incoming particle impulses, for example 30 and 34, which occur in the j

: Graph A of Fig. 14- are shown at j : applied the input terminal 12 and get from this point! to pulse stretcher 50 and via line 278 to a differentiator 432, a comparator 434, a lower threshold | . value circuit 436 and to the comparator 62.,

The differentiator 432 differentiates the signal 30. and generates a signal 440 at its output 438 , which in the graphic

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Representation B of Figure 14 is shown.

The lower threshold value circuit 436 also has a reference voltage source 442 and a potentiometer 444. The lower threshold level voltage is selected to be above the noise level, slightly above the baseline of the incoming pulses and is shown at 446 in graph A of FIG. When the signal 30 * the lower threshold voltage 446 at time t. exceeds, an output signal from the comparator 432 is generated; as shown as square wave 448 in graph C. The wave 448 lasts as long as the signal 30 exceeds the lower threshold value, ie until your point in time t ^ _. The leading edge of the shaft 448 is scanned by a leading edge detector 450 to detect a trigger tip 452 at time t. as shown in graph F _; and is also used to set a j RS flip-flop 454.

The output signal 440 of the differentiator 432 is applied to a comparator 456. It can be seen that the second input terminal 458 of comparator 456 is grounded so that only one output occurs from the comparator while the input 'on line 438 is positive. The output of the comparator; 456 thus consists of a square wave 460 (graphical representation. 'Position D), and is produced only during the portion of the signal 440 j which is positive.

At this point the meaning of square wave 460 should be verified will. Since the original particle pulse 30 is applied to the I differentiator 432, the output signal is 440 is a graph of the slope of pulse 30. The slope of the leading edge of pulse 30 increases from the base. line to a maximum approximately in the middle of the rise, whereupon it drops until the slope is zero at the top.

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_ 49 -

In this way, the shaft 440 has a point approximately in the middle of the rise of the leading edge of pulse 30 and then falls to zero at the point in time at which the peak of pulse 30 is reached. After that, the slope becomes negative, and a waveform which is similar to the first half of shaft 440 is generated is. Therefore, the point of intersection with the baseline at the point in time tp very precisely determines the peak of the pulse 30, and, when square wave 460 is generated, its trailing edge occurs precisely at the time of the peak of pulse 30. By passing the signal 460 through a trailing edge detector 462 as an input to the reset terminal of the ES-. Flip-flops 454 derived a trigger pulse 464, which also set the exact time tp at which the peak of the pulse 30 occurs.

From the following it can be seen that the ES flip-flop 454 the sensor 14 only on the first tip of an incoming partial ^;

■ chenimpulses can respond, assuming that any pulses with multiple peaks on the basis of the pulse duration '.

'be rejected.

The output of the ES flip-flop 454 has a square wave 466 (graphic representation G) this pulse is given to a trailing edge detector 468, the output of which is then a Trig-; gerspitze 470 (graphic representation H) generated, which in turn ι is applied to the setting input of an ES flip-flop 472, ι The output of the ES flip-flop 472 begins at the time t £,, marks the exact time at which the Peak of impulse; 30 is reached _; and continues as a square wave 474 (graphic j illustration L) until the flip-flop at time t ^,! . ' is reset. The reset signal is derived from the trailing edge detector 108 on line 476. ;

Pulse 474 is used to open gate 478, to which the ES flip-flop 472 is connected by a line 480

209820/0912 o «e, NAL inspected

is. When gate 478 is turned on, a current begins from constant current source 482 into integrator 72 via line 484. This starts the generation of an impulse with a linear rise and a plateau, as shown in the graph M, the rising portion being generated by the current flow as long as the current is present flows. This means that the amplitude of the plateau section proportional to the duration of pulse 474, which is proportional to the period of time measured between t ~ and t-. It was already explained that tp is the point in time at which the peak P of the pulse 30 occurs, the following explanation shows the Derivation of the time tv.

The pulse 30 is also applied to the pulse stretcher 50, and the stretched pulse is the pulse 488 of the graph I, the member on the channel and at the input of 54- ¹ 58 damping occurs. The pulse 488 has an amplitude that is ■ equal to that of the pulse 30, ie the amplitude X. The switching; tion, however, maintains the level of tension created by the leading edge

ι

: of the pulse 30 has been reached and thereby generates a; Plateau with constant amplitude until the capacitors in the r circuit are discharged. The stretched pulse 488 is attenuated in the fe j attenuator to an amplitude that is a predetermined! is the partial value of the amplitude X and which in this case was chosen to be 50% j. The output of the attenuator 58 consists of the signal 490 (graphic representation J) and is sent to a

^; 492

₍ Threshold limiter passed on line 60. As a result

j prevents the voltage of pulse 490 from being applied to base4 ! reference voltage drops. Instead, it stays between pulses j at level 494, which is slightly above baseline 496. The purpose of this arrangement is to ensure that between pulses the voltage on path 498 is less than the voltage on path 500.

The output of the threshold limiter 492 occurs on the

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Line 500, which is one of the terminals of the comparator 62, the other terminal carrying the original particle pulse 30. This is shown by the two shafts 490 and 30, which are arranged one above the other in the graphic representation J of Pig.14. The two signals are compared by the comparator 62 which produces an output signal 502 of constant amplitude during the period in which the pulse 30 exceeds the signal 490. This is from a point in time shortly after the point in time t. by time t, the fall and the resulting wave 502 occurs on a line 504 (graph K) and is applied to the cooling flank detector 108. This detector generates a trigger tip 506 on line 476 (Graph 0). It should be noted that the point in time t ^ at which the trigger peak 506 occurs is the point in time at which the particle pulse 30 has fallen to the partial amplitude value selected by the attenuator 52, ie in this case 50 % of the original amplitude X.

There are now two trigger pulses 470 and 506 which occur at the point in time at which the pulse 30 reaches its peak or at the point in time at which it has fallen to 50% of its amplitude X. It has already been explained that the trigger tip sets the RS flip-flop 472 to trigger the square wave 474, and it can now be seen that the trigger tip 506 is applied to the reset terminal of the flip-flop 472 so that the square wave 474 is terminated at time t 1 . I.

The length of the plateau of pulse 486 is given by time j point is determined when the integrator's short circuit device 72 is energized to bring the integrator to its minimal state; Reset charge. The trigger tip 5Ο6 is triggered by the | Line 476 is applied to the univibrator 112, which begins to generate a square-wave pulse 580 at time t shown in graph P. Of the

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Rectangular pulse 508 is sent to the trailing edge detector 122 and via the. Line 510 is applied to AND gate 112 and to input line 224 of memory circuit 242 for the minimum duration. The pulse applied to trailing edge detector 122 generates a trigger pulse at the end of the univibrator .112 duration. This duration is chosen so that it is sufficient so that a well-defined output pulse can be emitted by the sensor 14. In the example described, this pulse extends from time t ₇ to time tj- .. The output pulse always has exactly this duration. At that time, a trigger tip (not shown) occurs at the input 124 of the univibrator 128. This univibrator emits a rectangular pulse 512 (graphic representation Q. of FIG. 14) which is of sufficient length to discharge the pulse stretcher 50 via the line 132 and short-circuit the integrator 72. This takes place after the processing of a particle pulse JO has been completed and puts the sensor 14 in readiness to receive the next pulse.

The AND gate 120 outputs the square wave signal 508 to the line! 142 further to the gate 144 during the time from t-, - t, -

0 5

to open only when a signal is present at its input connections 116 and 140. It has already been shown that the signal 5Ο8 occurs on line 116 in each case. the Storage circuit 242 cooperates with amplifier 254 with the gain adjuster 270 together to generate variable levels 252 and 256 (graph M) and; to provide a level of comparison for comparator 244 that! the generation of the required output signal on the line 140 acts as shown as logic level 514 on graph N. '

As long as pulse 486 does not exceed level 256, it is on Signal is present on line 140 and the AND gate has an output on line 142 between times t, and tr. Gate 144 is opened at the same time and the

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Output 16 receives a pulse 5 ^ 6 (graphic representation E in Fig. 14), which has an amplitude X which is equal to the amplitude of the stretched pulse 488 and has a fixed duration. Of the Pulse 508 is actually a blanking pulse, the one Part of the stretched pulse 488 cuts off and allows that part to pass to the output terminal 16.

The particle pulse to be processed next is the pulse 34 generated by the particle Y passing on the path through the opening of FIG. It has two peaks 36 and 38, the amplitude of the first peak being Y. In FIG. 14, this pulse 34 is shown in graph A. It should be noted that it has a longer duration than the pulse 30 _: and that it is not certain that the amplitude Y is proportional to the size of the particle which produced it. It is therefore desirable $ <iie'ser pulse is not observed and that the \ gate 144 is not opened when it is driven by a signal 518, which is an equivalent to the pulse 508 (graph E).

When the pulse 34 crosses the lower threshold 446, a square wave 520 is generated between times tg and ty, ^ (Graph C). This is the output of comparator 434 that appears at the input of leading edge detector 450. In the same manner as described in connection with the processing of the pulse 30, a trigger tip 522 (graph F) is generated to set the RS flip-flop 454 and generate the beginning of a square wave 524 (graph G) . In the meantime, the pulse is differentiated in the differentiator 432 advantage 34 so that a differential shaft 526 (graphical ^{representation;} position G) occurs on the line 438th Since the impulse 34. : has two peaks, there are three points with a slope equal to zero, and these points are at the times tr ,, to and tg '

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_ 54 -

given where shaft 526 intersects the baseline. If the Compare wave 526 with earth potential 458 in comparator 456 only the positive parts of the wave 526 lead to output signals, which the square-wave pulses 528 and 530 (graphi- · see illustration D). The trailing edge detector 462 generates the trigger peaks 532 and 534 · at times tn and tq (Graph E), both of which are connected to the reset input terminal of RS flip-flop 454 is applied v / ground. The first trigger pulse 532 is used to reset the RS flip-flop 454 and the second trigger pulse 534 has no effect, v / eil the flip-flop has just been reset. Resetting the RS flip-flop 454 turns the generation of the square wave 524 on the time ■ tn ended. This causes the trailing edge detector 468 a trigger tip 536 (graphic representation; position H) at time tn to the input to the second: RS flip-flop 472 applies.

From the foregoing it can be seen that the in Fig.13 The sensor shown for particles with an axial path is only responsive to the first tip 36 of the shaft 34-, with that of the signals generated second peak 38 are disregarded.

The particle pulse 34- is simultaneously sent to the pulse stretcher 50. and the comparator 62 is applied. According to the method described in connection with ". The pulse 30, the pulse 34 is attenuated in the attenuation element 58 and cut in the threshold value limiter j 492, and the resulting signal is then given \"

compared to the original pulse 34 in the comparator 62. The resulting signals are shown as 538 in graph I and as 54-0 in graph J. The output of comparator 62 is the square wave 542 of graph K, the leading edge of which has no meaning but whose trailing edge is precisely time ty , Q marked at which the trailing edge of the pulse 34 stops below 50% of the amplitude Y. This pulse 54-2 occurs through the

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edge detector 108 to detect a tip 54-4- (graphic Representation 0), which is sent via line 476 to the Reset connection of the RS-Flip-Ii'lops4-72 and to the input of the Univibrators 112 is applied.

The RS flip-flop 4-72 generates the pulse duration measurement signal 54-6, (graphic representation L) from the time tn at which the first peak 36 of the particle pulse 34- occurs, up to which Time t ^ Q, .at which half the amplitude of the pulse 34- reached is. This flip-flop is triggered by the trigger tip '536 set and reset by the trigger tip 544-.

The pulse duration measuring pulse 546 opens the gate 4-78, and the integrator 72 begins to generate the integrated pulse 54-8 (graphic representation M), the rise of which increases linearly from the time t 1 to the time t 1 _Q . Then the plateau is created. It can be seen that the pulse 54-8 exceeds the maximum voltage level 256 from time t to time t ^ o. Therefore, a change in logic level occurs in the output of comparator 24-4- on line 140 during this time period from t-tp. This is represented by the negative square pulse 550 in the graph N. The evaluation pulse 518 is generated as ^{: is shown} in the graphic representation P, and the discharge ^! pulse 552 is generated as shown in graph Q; is shown, both in the same manner as was described in connection with the processing of pulse 30. Although discharge pulse 552 serves to discharge the capacitors of pulse stretcher 50 and integrator 72, evaluation pulse 518 has no effect to the gate 14-4- because this evaluation pulse occurs while the pulse 550 is present to indicate that the duration of the pulse 34 · from its peak to its half-value amplitude is greater than the maximum duration represented by the voltage 256 .

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It should be noted that the processing of pulse 34- has no effect on the memory circuit for the minimum duration, which also stores the duration of the last pulse processed to produce an output on terminal 16.

Reference is made to FIGS. 15 and 16 below. The sensor 14 shown differentiates the particle pulses twice in order to find the points of minimal change in the steepness of the particle pulses. These points mark the maximum steepness of the original pulse. Since a particle pulse with more than one peak is illegal, this embodiment of the sensor has a circuit for rejecting such pulses, even if their pulse durations correspond to the pulse duration ^; correspond to the criterion that is set by the memory circuit for the minimum duration.

The two considered particle impulses are again the same as those generated by the particle X and the particle Y on the path 24 and the path 26 of FIG. This import \ pulse are designated as 30 and 34- in Figure 16. They are both applied to the input terminal 12 of the sensor 14-. First, the pulse 30 is processed and this process is described.

The pulse 30 is applied to the pulse stretcher 50, the i

stretched pulse 560 (plot P of Figure 16);

which has the same leading edge as äs: pulse 30, but: has a flat top that is at the same amplitude as

the maximum amplitude of the pulse 30 is. The duration of this ■

Pulse 560 is triggered by inputting a discharge signal to the;

Pulse stretcher 50 controlled as will be described. j

At the same time, the particle pulse is sent to circuit 436 for the lower threshold is applied to suppress the noise level and trigger signal for the evaluation univibrator Ή2 to accomplish. The threshold value is determined by a voltage

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-Vl-

source 442 and variable resistor 444 to provide one input 500 to comparator 62, the other terminal being line 498 from input terminal 12. The threshold for the noise level is 446, as shown exaggerated in graph A. A signal 448 (Graph B) has a square wave that appears on the output line 504 throughout the time that the input particle pulse 30 exceeds the noise level threshold 446 between times t. and tr, exceeds. The trailing edge detector 108 generates a trigger peak (not shown) at the time tr, and applies this trigger peak via the line 476 to the evaluation univibrator 112, whereupon the latter emits the evaluation pulse 462 (graphic representation G) between the times tn and t _g . This evaluation pulse is sent via line 116 to one of the inputs of the veto AND gate 120 and via line 226 to another return flange.

jk detector 122 applied. This detector generates a trigger tip (not shown) at time tg which is sent to the reset univibrator 128 is applied over line 124 and a reset pulse 564 (graph H) is applied between the Times to and tq generated.- This pulse is used to discharge of the pulse stretcher 50 is used to the integrator 72 as well reset two toggle switch flip-plops, which are still described

j "become 6s. The connection line for the reset functions is denoted by 132. '

The incoming particle pulse 30 is also applied to the first diffentiator 432, which differentiates the pulse 30 and generates the 'wave 440 (graph C) in the period just before time t ^ and just after time tr. This signal represents the slope of the particle _{pulse 30 and therefore has a peak at t 7} , the point of maximum slope of the leading edge of the pulse 30, a zero crossing at the point in time _; t ^, at which the pulse has the peak or the slope equal to zero, and has another peak at tr, which is the point of maximum slope of the trailing edge of the particle pulse 30. This

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Pulse 440 is through. an amplifier 566 is amplified to change its timing. It is then applied to a second differentiator 568. The output of the differentiator 568 is the differential of the wave 440, as shown at 570 in the graph P of H ¹ Xg.16, and represents the rate of change in the slope of the wave 30. The minimum rate of change occurs at the maximum slope of the leading edge and the trailing edge of the pulse 3p.

The differentiator 568 feeds a circuit 572 for one lower threshold used to suppress noise signals in that it serves a threshold value 574 with the aid of the Voltage source 576 and a voltage divider 578 is set. As shown, the threshold level is below the Enäpotential. A comparator 580 is therefore constructed and arranged in such a way that it only provides an output when the wave 570 falls below the noise level threshold 574. This takes place between times t 1 and tr or proportionally close to these times. The tip of the particle pulse 30 is a fill transition in wave 440 and a peak at t ^, · in wave 570. The output of comparator 580 occurs on a line 582 in the form of a square pulse 584 (graph E). This square pulse forms that Pulse duration measurement signal of the sensor 14, since it measures the time between the points of maximum slope on the leading edge and the trailing edge of the particle momentum 30 measures.

The square pulse 584 is sent to the integrator 72 and via a Line 586 is applied to another differentiator 588. In your Integrator 72 becomes the rectangular pulse duration measurement signal 584 used in the manner described above to generate a slope and plateau pulse 590, as shown in FIG

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the graph M is shown. From the point in time ty to the point in time te-, the amplitude of the pulse 590 increases linearly, v / whether the square-wave pulse 584 is integrated. From the point in time t, - the integrator holds its charge, so that the plateau is formed. This plateau is at an amplitude which is proportional to the duration of the pulse 584 and therefore also proportional to the duration of the pulse 30 between its points of maximum slope on its leading edge and its trailing edge. Since the integrator 72 is one of the components that are reset by the reset vibrator 128 v. ^r ^ ground allt its charge due to the influence of the reset signal 564 in the period from beginning tg at the time.

The integrated pulse 590 is at the maximum threshold level 256 in the comparator 244- compared, and, that ^ it this Level, no change occurs in the signal appearing on line 140, which is one of the input terminals of the veto AND gate is 120. The operation of the memory circuit 242 for the minimum duration is as shown in FIG Connection with the memory circuit of Fig.7, 11 and 13 is described with the exception that the AND gate 240.is lower input from feedback line 592 from the output of the veto AND gate 140 in the form of a square wave 594- (graphic Representation 0).

The rectangular pulse duration measurement signal 584, which is in the differentiator 588 is differentiated, produces positive and negative Trigger pulses 596 and 598 (graph F) shown in negative trigger pulses 600 and 602 (graphic illustration E) converted by a rectifier 604 to ground. These latter ' Trigger pulses are applied to the lower terminal 606 of a veto AND gate 608, and if they are passed, who the it is applied to a first toggle switch flip-flop 610. Each of the Trigger peaks 600 and 602 indicate a zero crossing of the wave 57O, which corresponds to the moment of maximum slope in the original

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- 60 lichen impulse corresponds to 30.

Both the toggle switch flip-flop 610 and the series-coupled KippsehalteI ^- flip-flop 612 have previously been reset by the reset univibrator 128 over the line 132, so that signals corresponding to the logic 0 on their output paths 614 and 616 between Impulses occur. Under these circumstances, two signals corresponding to logic 0 are received by an AND gate 618, which in turn outputs a signal corresponding to logic 0 to the veto input terminal 619 ″ of the veto AND gate 120 in order to switch the gate on Otherwise there is no veto signal on the veto input to 620 of the veto AND gate 608, so that trigger pulses received on the line 602 are passed on to the toggle switch flip-flop 610. The first peak 600 toggles that Flip-flop ^ 610 and generates a square wave 622, (graphic representation J), which begins with the first trigger pulse at time t ^ and ends with the second trigger pulse at time t, - Trailing edge detector 624 a trigger tip (not shown) that the -

it toggle switch flip-flop 61.2 tx'iggert so that an output signal on line 616 emits. This consists of a square pulse 626 (graphic representation K), which begins at time t ^ and _{ends at time t Q} when the toggle switch flip-flops ■ are reset. There is therefore a signal corresponding to logic 1 at the upper input 616 of the AND ^{gate 618 and a signal corresponding to logic 0 at the lower input 614 of this:} AND gate. The evaluation pulse 594 (graphic representation 0) begins at time t ^ and ends at time t _ß . During this period of time there is no veto signal on line 619 because only two zero crossings occurred in the second differentiated wool * 570, which means an essentially perfect pulse 30. There is therefore a signal level 628 on line 619 (graphic illustration N) and the evaluation signal 562 (graphic illustration G) on line 116. Since all

ι ** λ ^ - ϊ -, .- w 2 0 9 8 2 0/0912 ^{BAD 0} ^ GiNAL

conditions for passing a signal through the veto AND gate 120 are given, the evaluation signal 594 appears line 142, opens gate 144- and leaves part of the stretched pulse 560 su the connection 16 between the points in time tr-, and t penetrate. This output signal points the derived pulse 630 of the graph Q on.

From the foregoing it can be seen that there are two criteria for generating an output signal there. The first criterion is the same as that given above regarding the maximum

■ the level with which the integrated pulse is

. is like. The second criterion is an additional criterion that of the number of Kull transitions of the second derivative of the Particle momentum depends. This will be discussed in the following with the processing of a pulse having multiple peaks, such as pulse 34 described. It's closed note that although the pulse duration is between the points of maximum slope on the leading edge and the trailing edge of a

• Impulse satisfies the impulse duration criterion, it is possible that the occurrence of more than one point a regularx-d-drigen Pulse, so this pulse should be filtered out. For this reason, the second criterion is in the probe 14

'from I ¹ Xg. 15 built in.

. It is now at the pulse 34 (graph A);

; considered when it passes through the comparator 62. He produces ^; a square wave 632 between times t ^ Q and t -. * j

'(Graph B) · The trailing edge of shaft 632 '. conducts the evaluation pulse 63 ^y + (graphic representation G) between- '. see the times tp ^, and top ^{un <} i a reset pulse (graphic representation H) between the times t ^ p ^unci ί t23. The first derivative of the momentum 3 ^ is the wave 638, which has two positive peaks at t, p and "^ r ₇ , a negative peak at t ^ c and three zero transitions at t ^ / ,, tg and t ^ g The wave 640 obtained by the second derivative has four Hullu processes at t ^ p »^ 15 '* 17 ^UIld -" ¹ MQ' ^Daner shows

2Q9820 / 0912 8AD ORIGINAL

the output of the comparator 580 has two square pulses 642 and 644 (graph E) which together represent the pulse duration Mcßsignal, which consists of two parts "because the pulse J4 has two peaks. Ls therefore gives four edges of maximum slope. This signal group is integrated in the integrator 72 and generates a pulse 646 with two plateaus (graphic illustration Ii) with a first rise between the times tp and t- _r , which corresponds to the rectangular pulse 642, - a lower plateau section, the. t ψ on the maximum of the first rise of the Zeitpurikr _L -. to t ,,, -, acomplished amplitude value remains .einem second rise between times t _r, and tq, corresponding to the Rechüeckinipuls 644, and with a second. Plateauabsciraitt between

■ the times tq and tp _O. The pulse 646 exceeds the upper limit threshold 256 from time t (the between

^! times t., - t ^ and q is) until the time ^ 22 * Therefore, the line 140 a veto signal supplied from the comparator 244 648 (graph IT). Therefore, no matter what happens on lines 116 and 619, no signal will appear on line 142 and gate 144 will not open.

It is assumed for the moment that the duration ¹ of the; The signal combined with the two square-wave pulses 642 and 644 ^{: is} so large that the integrated signal 646 does not exceed the threshold value 256. In this case there is. two or more peaks at pulse J4, which means that the amplitude is not a correct measure of the size of the particle generating the pulse. It is desirable not to send this impulse through the sensor 14, although its duration is essentially that of a desired impulse. This is achieved by the circuit in the lower right corner of the block diagram.

Generate the two Rschteckimpulse 642 and 6Vt- laare of positive and negative peaks 648 and trigger 6 ^ 0, the graphic in dec "representation ¥ after passage through the Differentia-

2Q9820 / 0912 sad original

gate 588 are shown. These peaks are converted into negative peaks 652 (graph I) by the rectifier 604- and then run to the toggle switch flip-flops 610 and 612 through the veto AND gate 506. First there is an output signal corresponding to a logic 0 from the Flip-flops on lines 614, 616, 619 and 620. At the time t ^ _2, the first of the trigger tips 652 arrived and flip-flop 610 flipped over to generate the beginning of the square pulse 654 (graphic representation J). The second of the trigger spikes 652 arrives at time tc- and ends the pulse 654. During this period of time, an output signal corresponding to logic 1 was present on line 612, but logic 0 remained on line 616, so that the before Arrival of the first trigger point continues. As soon as the second of the trigger tips 652 arrives, a signal corresponding to a logic 0 occurs again on the line 614, and a square-wave pulse 656 (graphic illustration E) begins. A signal corresponding to logic 0 is still present on lines 619 and 620. As soon as the third of the trigger peaks 652 arrives at the time t ^, it triggers a second output signal 658 (graphic representation J) from the first toggle switch flip-flop 610, which does not influence the return flap detector 624 up to the time tpp. During the period from t ^^ - t ~ o, however, signals 656 and 658 are on lines 614 and 616. Therefore, the UHD gate 6i8 generates a veto signal 660 (graphic representation L), which indicates the further passage of trigger tips blocks by the veto-AND gate 608 ', while at the same time it blocks the veto-UlID gate 120 and prevents it from forwarding the evaluation signal 634. As a result, there is no output on terminal 16 because the analog gate 144 has not opened to receive part of the ^: stretched pulse 662 (graph P).

In the preceding description, exemplary embodiments of sensors for particles with an axial path, which work analog or digital and which are sent to the. Exit either

209820/09 12

the a reconstructed (artificially generated) representation of the; Particle impulse or the particle impulse itself. Furthermore, the basic execution examples with an arrangement for finding the Irnj ml Samplitude in the case of the iTipul f.mi lt; e, a time sequence cenor, a logic control circuit and an iJpeieherschali.img fiber minimal duration can be improved either in combination or individually. The devices for scanning the speed also ensure that inaccuracies in the anterior and posterior flanks of the particle axis do not cause any errors, and that particle pulses can be closed with iaelu'cren, sharp points 'ungsbeispiel and its j \ ^ln.! a2idlungen are of course intended for use in a device, -the a Coulter particle iinalvsator used.

SAD ORJGINAP =,

209870 / 0.9 12

Claims (58)

- 65 - Pa t e n e tansprüch Method of analyzing the size of particles for scanning "the pulses generated by the particles which are generated as particles pass through the detector opening of a pulter measuring device, the method between those particles which travel along as they pass through the opening move along the axis of the same, and distinguishes those particles which move outside the axis of the opening when passing through the opening, characterized in that the duration of at least one predetermined part of each particle-generated pulse is measured at a predetermined partial value of its amplitude, that a pulse . continuous measuring pulse with constant amplitude and predetermined duration: is derived from the fact that the pulse duration measuring pulse is converted into an electrical quantity with such a value that is proportional to the duration of the pulse duration measuring pulse that an electrical effect is generated which a reference value for a maximum desired value of the ImpuLodauer measuring pulse, the reference value distinguishing between electrical measured values, which are pulses from those particles which pass through the detector opening outside the axis of the opening, and electrical measured values which represent other particle-generated pulses, of which pulse duration -T / e 3 pulses π it shorter pulse duration than the maximum value of the reference value can be derived that each of the electrical measured values is compared with the reference value and thereby an excitation signal of a first type, if the electrical measured value does not exceed the reference value, and a excitation signal of a second type is generated when the measured value exceeds the noise value that "an electrical signal is derived from each Aw particle-generated pulse, and that each of the derived electrical signals is allowed through or blocked, depending on whether it is an excitation signal de3 first type3 or dfis zv / eiten type-J generates h-it. 209870 / nSl? 2. Procedure after address. 1, characterized by {^, that the electrical quantity into which the pulse is continuously converted to measuring pulse, egg non electrical clock signal pulse has, and that no word the amplitude dors electrical Taktsignnlimpulses has that the electrical effect a Signal level i-y.t, and that the time signal! pulse is compared with the signal level in order to to generate rain signals of the harvest and the second type, 3. Verfa.hren according to claim 1 or 2, characterized in that that before the first step the comparison eu> e • Reaction to the smallest value of the converted electrical Size value is generated, which is in front of the just scanned, part of the generated pulse occurs in order to adjust the size of the "reference value of the electrical effect," where is the smallest value; such a value that the prevailing reference value at the time of its occurrence does not exceed. 4. The method according to any one of claims 1 to 3> some of the other partially generated pulses being derived from particles passing outside the axis of the aperture, however, have a duration which does not exceed the reference value, characterized in that for measuring this Impulses and for passing on derived, electrical ones Signals the mean amplitude of each incoming particle pulse is sampled, and that this mean amplitude in the pulse duration measurement and in the derivation of the pulse duration ~ measuring pulse "l sas is used, the derived electrical signal being the has the same amplitude as the mean amplitude. 5. The method according to any one of claims 1 to 4, characterized in that the ImpulsdaüermnrfsuriP, aas the measurement of the duration of the part of the Tei-loh-mitiip-ul.vns consists, c ^: it between the point of minimum slope on its leading edge and a Point with a predetermined amplitude value 209820/0912 SAD ORJGfNAL - 67 is on its back flank. 6. The method according to any one of claims 1 to 4, characterized in that the pulse duration measurement in the measurement the duration of the part of the particle impulse that lies between the points of maximum slope on its fore wing and its rear flank lies. 7 · The method according to any one of claims 1 to 6, characterized marked that dis number of tips each? Particle pulse is sampled and a signal is generated to the derived block electrical signal, always if more than a νor "certain acceptable number of peaks on a particle's pulse is available. 8. Apparatus for analyzing the size of particles, for performing the method according to claim 1, with an axial trajectory scanning probe for use with a Coulter measuring device in which particles pass through a detector opening and generate particle-generated pulses, the particles if 3ie closest iung pass at the axial Baim by the Deteküoröff?, produce desired part double pulses with such amplitudes au proportional in the best approximation to the respective Toilehengrößen _f no that the desired, teilchenerzeugton pulses have a determined "approximate pulse duration, and wherein the T '.'ilchen, d: i π pass through the detector opening on paths that are offset from the axis, generate other particle pulses with amplitudes that are not necessarily proportional to their respective sizes and have pulse durations that are longer than dor certain approximate impulse tend to last, characterized in that the sensor (14) is constructed and arranged in such a way that it responds to the desired partial impulses in a first way and to the other partial impulses in a wide range and contains: an input connection ( 12) and an output connection (16), a ^ n channel (54) for the 209820/09 12 Passage of electrical signals between the terminals, a switch (144) in the channel to control whether an electrical signal occurs at the output terminal (16), the input terminal (12) being constructed so that the desired and the other particle-generated pulses are applied, a measuring device (50, 52, 58, 62) for measuring the duration of at least a predetermined portion of each adjacent particle-generated pulse at a predetermined sub-value of the amplitude of the same, the measuring device being constructed to provide a pulse duration Measuring pulse (74) with the measured pulse duration and a constant amplitude derives an electrical converter {72; 174) to convert the pulse 'continuous measuring pulse into an electrical variable (76, 155) with. a value which is proportional to the duration of the pulse duration measuring pulse, an electrical device (80; 178; 244) for producing an electrical effect (88; 252) which represents a "reference value for a maximum desired value of the pulse duration measuring pulse, wherein the electrical _input; direction the electrical variable with the reference value and compares an excitation signal of a first type "if the elektrisehe size does not exceed the reference value, and acceleration signal produces an exciter 'of a second type when the electrical quantity exceeds the reference value. and circuitry (120) for applying each of the excitation signals to the switch in the channel to allow passage to the output port only of the electrical signals derived from the desired, partially: generated pulses are derived. j 9 »Device according to claim 8, characterized by 'a modification circuit (242) with an input (246) and an output (268) connected to the electrical device for T.Todify the reference value (252) of the electrical effect before its comparison with the electrical quantity by the electrical, see device is coupled, wherein the modification circuit (242) is connected and constructed so that it is on each of the electrical quantities responds to the attraction value in direct relationship with each of the electrical quantities 209820/0912 yours, which has such a numerical value as its value, the lower, than the currently existing reference value. 10. The device according to claim 9 »characterized in that the modification circuit (242) has a tolerance setting device (270, 254) to effectively increase the size of the modified reference value, thereby increasing the electrical The device generates the first type of excitation signal, even if the value of the electrical effect is modified Does not exceed the reference value by more than a tolerance (256) determined by the tolerance setting. 11. Apparatus according to claim 8 or 9 »characterized in that the modification circuit (242) elements (248, 258) for comparing the electrical effect with one Tension level and to reduce the tension level to a balance, wherein the elements with devices (260, 262) are arranged to hold the lowered voltage level as in a memory and around the lowered Output voltage level as an output signal (250) to the electrical device in the form of the modified reference value. . 12. Device according to one of claims 8 to 11, characterized in that the Beaufs a hammer circuit Gate (120) which is arranged between the electrical device (80; 244) and the switch (144) that a Evaluation pulse generator (108, 112) connected to the gate is to an evaluation pulse (114, 212) from the pulse duration measuring pulse to excite the gate and operate the switch so that any signal or part of it, that is present in the channel (54) only for the duration of the evaluation pulse is passed on, the excitation signal (164) of the second type determining the operating mode of the gate blocks in order to prevent the evaluation pulse from affecting the switch, and the excitation signal of the first type3 the gate (120) switches on. ' 209820/0912 13. Device according to one of claims 8 to 12, characterized in that the electrical converter (72) the Pulse duration measuring pulse (74) into an electrical time signal pulse (76, 156) converts that the value of the same the amplitude of the electrical timing signal pulse is that the electrical effect is a signal level (88, 252) and that the electrical Means (80, 244) compares the timing signal pulse with the signal level to determine the excitation signals of the first and second Type. 14. The device according to claim 13 »marked-marked, that the converter has an integrator (72) which responds to the pulse duration measuring pulse which the time signal pulse generated as a pulse (76, 156) with a flat, plateau-like top and a linear rise. 15. Device according to one of claims 8 to 12, characterized in that the electrical converter (174) is so ^: constructed that it converts the pulse duration measuring pulse into a plurality, number of clock pulses, so that the value of the same from the number the pulses which can be passed on during the duration of the pulse duration measuring pulse, and that the electrical effect is defined by a predetermined number of pulses, and that the electrical device (172) is so constructed that it the preset number of pulses with compares the number of pulses transmitted during the duration of the pulse duration measuring pulse in order to generate the excitation signals of the first and second types. 16. The device according to claim 15, characterized in that the electrical device has a counter (172) and a control circuit (178) for presetting the counter to respond to the preset number of pulses; the counter being arranged to generate the excitation signal of one type when the number of through the impulses transmitted to the pulse duration measuring pulse do not exceed the preset number, and that the excitation gas signal 209820/0912 nal of the second type if the number of the Pulse duration measuring pulse transmitted pulses the predetermined ' Number exceeds. 17. The device according to claim 16, characterized in that the counter is a down counter (172) in which every clock pulse passed on by the pulse duration measuring pulse decreases the count of the counter, and in which the excitation signal of the second type is generated when the counter is up to counts down to zero, and the excitation signal of the first type is generated when the counter does not count down to zero. 18. Device according to one of claims 12 to 17 »characterized in that the electrical device has a device (82) to set a second signal level (96) which is equivalent to a minimum, desired ., Th duration of the pulse duration Is measuring pulse, and that the application circuit has a terminal (102) to which; To put switch (144) out of operation when the pulse duration measuring pulse does not exceed the second signal level, so that no electrical signal (146) passes to the output terminal (16) if it is derived from a particle pulse whose duration is insufficient to to generate a pulse duration measuring pulse exceeding the minimum desired duration. 19. The device according to claim 18, characterized in that that the electrical device also has a device. device (100) to the pulse duration measuring pulse against the; comparing a second signal level (96) to generate an excitation signal of a third type when the pulse duration measurement pulse exceeds the second signal level and to produce an excitation signal of a fourth type when the pulse duration measurement pulse does not exceed the second signal level, and that the excitation signal of the first type and of the third type the Gate (120) activates and the excitation signal of the second and fourth type blocks the operation of the gate in order to have an effect, of the evaluation pulse (114) to the switch (144) 209820/0912 - ζ d. - prevent the evaluation pulse actuating the switch when the pulse duration measuring pulse reaches the first signal level (88) does not exceed, but exceeds the second signal level (96). 20. The device according to claim 19> characterized in that that the gate is a veto AND gate (120) with a Veto input (HO) and two UTTD inputs η (102, 116), where one AND input via a connection (116) to the evaluation pulse generator (108, 112) and the other AND input is connected via a connection (102.) to the electrical device (82) in order to receive the excitation signals of the third and fourth "Type, the excitation signal of the third type being a signal corresponding to logic 1 and the signal of the fourth type is a signal corresponding to the logic 0, and that the veto input is switched on via a connection (140) to receive the excitation signals of the first and second types, the excitation signals of the first type being a the signal corresponding to logic 0 and the excitation signal of the second type is a signal corresponding to logic 1. 21. Apparatus according to claim 19 or 20, characterized characterized in that the electrical device has two comparators (92, 100), one of which is a comparator (92) compares the pulse duration measurement pulse with the first signal level (88) and generates an output signal (106) representing the excitation signal of the first and second types and of which the second comparator (100) compares the pulse duration measuring pulse with the second signal level (96) and an output signal which represents the excitation S3 signal of the third and fourth types. ■ 22. Device according to one of claims 8 to 21, characterized in that the device (58, 62) for Measurement of the pulse duration the duration of the entire, particle-generated pulse (30, 34) at a predetermined partial value (64, 209820/0912 - 73 150) measures its amplitude. 23. Device according to one of claims 8 to 22, characterized in that the measuring device has devices (50, 58) to generate an electrical wave (64, 150), the duration of which is considerably longer than the duration of the particle pulse from which the electric wave is derived, and which has a constant amplitude over a substantial Has part of its duration, the amplitude being the predetermined partial value of the amplitude of the particle pulse from which it is derived, and that the measuring device has a further • direction (62) has to match each particle pulse with the electrical Compare wave over a period of time when the amplitude of the wave is constant *. . 24. The device of claim 23 marked thereby 'characterized that performed by the by the measuring device . Compare an output signal (74, 154) is only generated while. rend every particle pulse exceeds the amplitude of the electrical wave_, the output signal being the pulse duration measuring pulse, is. 25. The device according to claim 23 or 24, characterized in that the measuring device has a pulse stretcher (50) ^! and a circuit (58) for attenuating the output of the pulse ] ; has stretchers. '; - 26. The device according to claim 25, characterized in that | • shows that the pulse stretcher (50) is in the channel (54) ' ^: can be seen and the electric wave to the output port ^: (16) only passes on to the extent that it is passed on by the Switch (144) is enabled. 27. Device according to one of claims 12 to 26; characterized in that a signal delay device ' (52, 290) for delaying the uptake of the generated particles; 209820/0912 . - - 74 - Pulses through the channel (54) are provided, and that the evaluation generator (108, 112) is so constructed and arranged that the "gate (120) in the apply circuit to the output terminal (16) passes on each of the desired particle pulses (300) as it is delayed by the delay device is. 28. The device according to claim 27, characterized in that the first section (52) of the signal delay device between the input connection (12) and the input (68) of the measuring device (62) is connected to the recording . me of the particle pulses (30 ', 34') through the measuring device delay. 29. The device according to claim 27 or 28, characterized in that 'that at least a part (290) of the Signalver-. delay device an input coupled to the input connection (12) and an output connected to the channel (54); has gear. 30. The device for claim 29, characterized; indicates that both the first section (52) and the • the first part (290) of the signal delay device form two delay elements connected in series. 31. Device according to one of claims 8 to 26, characterized in that the electrical signals from the .desired particle impulses with the help of a signal form ming device (50, 112, 220) are derived, which are sent to the Input port (12) is coupled in the channel (54) and operates in such a way that output pulses (146) predetermined duration are generated, which the respective amplitudes (X) of the desired particle pulses (30). 32. Device according to one of claims 8 to 31, characterized in that a logic control circuit (238) is provided which has a gate (274) which is shown in 209820/0912 Series with the channel (54) connected to the input terminal (12), the logic control circuit having a structure and means (276, 278, 279, 232, 236) to provide the gate for blocking the channel in dependence on to close predetermined logic signal conditions in parts of the sensor. 33 · Device according to claim 32 »characterized in that that the control logic circuit (238) has such a structure and an arrangement (232, 236, 279) that it responds to a logic state during the time the sensor is processing a pulse of particles in order to respond her gate (274). to close during this period. 34. Apparatus according to claim 32 or 33, characterized characterized in that a time sequence generator (208) with several outputs (232, 236, 279) is provided which are connected are to control the operating steps of the logic control circuits, the time sequence generator being such Terminal (108, 206) and arranged so that it is responsive to a pulse of particles as it passes through the probe is processed. 35. Apparatus according to claim 34, characterized in that the time sequence generator (208) has an input (108) which acts on the output from the pulse duration measuring device (62) responds. 36. Device according to one of claims 32 to 35 j I ; characterized in that said control logic circuit (238) has a structure and arrangement (268) such that it; is responsive to voltages at the input terminal (12) to provide j then to close the gate (274) whenever the voltages exceed a preset level so that Only complete particle impulses can ever enter the sensor. j 209820/0912 37. Device according to one of claims 8 to 36, at which some of the other particle impulses have amplitudes which are not necessarily proportional to the sizes of the respective Particles are, however, pulse lengths equal to the determined have approximate pulse duration, characterized in that the ITuhler (H, Fig. 11) allows the passage of electrical signals allowed to the output terminal derived from the particle-generated pulses, and that the sensor is one with the Input terminal (12) has electrical circuit (340 378) connected to the amplitude of each particle-generated pulse at the center of each particle-generated pulse and this mean amplitude to the measuring device for the "pulse duration measurement and to deliver the pulse generation. ' 38. Apparatus according to claim 37, characterized in that the circuit for finding the center point includes a circuit (354) for receiving each particle pulse, a device (356) for generating the integral of the particle pulse and a device (362) for comparing the Integral and the particle momentum to determine the point in time; where the amplitude of the integral and the amplitude ^: ', of the momentum are equal. - - 39. Apparatus according to claim 38, characterized in that that the midpoint detecting circuit a ^! Means (350-, 354, 356) to hold the integration voltage level for a considerable period of time - which is present at the point in time when the integral and the particle momentum have the same amplitude. 40. Apparatus according to claim 39, characterized in that the circuit detecting the center point a terminal (356) is connected to the channel (.54) so that the maintained integration voltage level is applied to the channel is given. . 41. Device according to one of claims 38 to 40, 209820/0912 characterized in that a device (358) is provided is to electrically adjust the relative amplitudes of the generated integral and the particle momentum so that the The point in time at which the integral and the particle momentum have the same amplitudes occurs in the middle of the particle momentum. 42. Apparatus according to claim 41, characterized in that the amplitude adjustment device (358) is a Having automatic device (368). 43 ·. Device according to Claim 41 or 42, characterized in that the amplitude adjustment device (358). is a divider arranged to divide the generated integral by the value of the standard value (260) des electrical effect. 44. Device according to one or more of claims 9 and 41 "to 43», characterized in that the amplitude adjustment device (358) connected to the modification circuit and automatically by the reference value (260) of the electrical Effects is controlled. 45. Device according to one of claims 8 to 44 »characterized in that the measuring device for the duration of the particle-generated pulse comprises elements (432 ... 500) for the duration of the portion of a particle-generated pulse to measure the distance between the point of the first occurring mini-f paint slope is on its leading edge and a predetermined point on its trailing edge. 46. The apparatus of claim 45 'characterized in that the measuring elements an electronic Differentia- ^ tor (432) comprise any teilchenerzeugten pulse for generating a first differential signal for \. _; 47. Apparatus according to claim 45 or 46 » characterized in that the measuring elements are constructed and arranged 209820/0912 , net are that they have a predetermined partial value amplitude of the Particle momentum measures to define the predetermined point on the back plank at which the momentum duration measurement ends. 48. Device according to claim 47 _f characterized • indicates that the measuring elements for determining the predetermined point on the trailing edge include a pulse stretcher (50); and an attenuator (58) which generates an attenuated signal having the partial value amplitude and has a comparator (62) for comparing the amplitude of the attenuated signal with the L · ' trailing edge of the particle pulse. 49. Device according to one of claims 8 to 44, ; characterized in that the device for measuring the ' , Duration of the particle-generated impulses elements (432, 568, 580, 572) to the duration at the part of the particle-generated j to measure pulse between the point of first \ Tenden maximum gradient occurring on the leading edge of the pulse and a predetermined point at the trailing edge of the immune ! pulses lies. ! 50. Apparatus according to claim 45, characterized shows that the measuring elements have a second generating a differential Means (568) for generating a second differential signal of each particle generated pulse. - " 51. The apparatus of claim 49 or 50, characterized \ in that the measuring elements and closed in such a ^way; are arranged so that they detect the point of maximum slope on the rear flank of the particle pulse3 and this j point as the predetermined point on the rear flank j define at which the pulse duration measurement ends. j 52. Apparatus according to claim 51, characterized in that the measuring elements have a second device (568) generating a differential in order to determine the maximum slope 209820/0912 - 79 - to define the rear plank of the particle momentum. 53 · Device according to one of Claims 50 Ms 52, characterized by a device (588 ... 624) which is connected to the second differential generating device (568) cooperates to generate the particle generated pulses with more than to block the acceptable number of peaks. 54. Device according to one of claims 8 "to 52, characterized by an electronic device (568-624) responsive to the number of peaks of a particle-generated pulse respond to a blocking signal (660) for the application '' ( circuit (120, 144) to generate whenever a particle-generated Pulse has more than a predetermined acceptable number of peaks. . 55. Device according to one of claims 8 to 54, characterized in that a pulse height analyzer (18) is coupled to the output connection (16) and is thus connected _; that it is responsive to any electrical signal delivered to the output port. ■ 56. Device according to one of claims 8 to 55, characterized in that a; C oulter particle analyzer or (-10) is connected to the two | " Fluid body, an opening (22) between the bodies, the bodies being iso-ΐ from one another with the exception of the opening: are profiled, and one of the fluid apertures is a Meßsus- '· board having particles, a circuit for establishing _(\ an electric field in the opening to provide a device to enable the Meßsuspension in the opening in flow j, wherein the flow generating ^! impedance in the opening through the passage of the particles is changed, and a detector: ■ having to detect the changes in impedance and wished the ER- '■ and generate unwanted particle pulses, the detector is coupled to the input terminal (12) · · 209820/0912 57. A method of sensing particle-generated pulses emitted by a detector aperture of a Coulter measuring device particles passing through are generated, the particles when they are closest to an axial path pass through the detector opening, generate desired particle pulses with amplitudes that are in the best approximation are proportional to the relative sizes of the particles, so that the desired, particle-generated pulses are a certain have approximately pulse duration and a maximum acceptable number of peaks, and where the particles passing through the Detector opening on track offset with respect to its axis run through, other particle impulses with 'such amplitudes that are not necessarily proportional to their respective sizes and more than the maximum number have peaks and / or pulse durations that tend to be longer than the determined approximate pulse duration, characterized in that the number of tips of each part j chenergenerated pulse and / or the duration of at least one i , predetermined portion of each particle-generated pulse at a predetermined partial value of its amplitude is measured that the ; The number of peaks and / or the duration is compared with a maximum reference value for the time of the peaks and / or the duration, an excitation signal of a first type if the · _; Pulse measurement does not exceed the reference value, and an excitation signal of a second type is generated when the pulse measurement exceeds the reference value, that an electrical signal. is derived from each particle-generated pulse, and that the derived electrical signal is either allowed to pass or blocked, depending on whether it is an excitation signal; of the first type or of the second type. 58. Apparatus for analyzing the size of particles with a sensor for an axial trajectory for use with a Coulter measuring device in which particles pass through a detector opening and cause partially generated pulses, in particular for carrying out the method according to claim 57 »characterized in that the 209820/0912 7T53T23 sensor (H) is thawed and arranged so that it responds to the desired particle pulses in a first way and to the other particle pulses in a second way and has: an input port (12) and an output port (16), a channel (54) for passing electrical signals between the terminals, a switch (144) - in the channel to control whether electrical signals appear at the output terminal, the input terminal being constructed so that the desired and other particle-generated pulses can be applied, a Measuring device (50, 52, 58, 62; 568, .580) for measuring the number of peaks of each particle-generated pulse and / or for measuring the pulse duration of at least a predetermined section of each applied, particle-generated pulse at a predetermined partial value \ its amplitude, an electrical device (80} 178; 244 '; 588 ...) for generating an electrical effect, which erwün a \ reference value for a maximum schten value of the number of peaks and / or the pulse duration measurement pulse, where j the electrical device compares the number of peaks and / or the pulse duration with the reference value and an excitation signal of a first type, if the pulse measurement the reference! value does not exceed, and an excitation ^{signal of a second type:} generated when the pulse measurement exceeds the reference value, and circuitry (120) for applying each of the excitation signals to the switch (144) in the channel (54) for passage; to allow only such electrical signals at the output port which are derived from desired particle-generated pulses. 59, device according to claim 58, characterized in that the measuring device has a circuit (568) to generate a second differential of the particle pulse, and a circuit (588 ... 624) to determine the number of transition points of the base line of the second differential to count and to generate the excitation signal of the first type only when the pulse train comprises two pulses , and to generate the excitation signal of the second type when the pulse train contains more than two pulses. . 209820/0912 Empty soap