US3603875A - Particle analyzing method and apparatus employing multiple apertures and multiple channels per aperture - Google Patents

Particle analyzing method and apparatus employing multiple apertures and multiple channels per aperture Download PDF

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US3603875A
US3603875A US823743A US3603875DA US3603875A US 3603875 A US3603875 A US 3603875A US 823743 A US823743 A US 823743A US 3603875D A US3603875D A US 3603875DA US 3603875 A US3603875 A US 3603875A
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aperture
channels
signal
volume
time
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Wallace H Coulter
Walter R Hogg
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Coulter Electronics Inc
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Coulter Electronics Inc
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    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
    • G01N15/00—Investigating characteristics of particles; Investigating permeability, pore-volume or surface-area of porous materials
    • G01N15/10—Investigating individual particles
    • G01N15/1031—Investigating individual particles by measuring electrical or magnetic effects
    • G01N15/12—Investigating individual particles by measuring electrical or magnetic effects by observing changes in resistance or impedance across apertures when traversed by individual particles, e.g. by using the Coulter principle
    • G01N15/134—Devices using two or more apertures

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  • time and volume related elements there is generated an output voltage which is proportional to particle volume per unit time over the entire particle system; hence, statistically valid data is available at all times during an analysis run, even in the event of a malfunctioning blockage of an aperture.
  • This invention relates generally to particle analyzing apparatus and method especially the type which use the Coulter principle described in U.S. Pat. No. 2,656,508, and more particularly is concerned with apparatus and method which utilize a plurality of apertures, each aperture having a plurality of channels for obtaining information.
  • the cited first copending application describes and claims apparatus and a method operating in accordance with the basic principles used in the apparatus of this invention.
  • a fluid suspension of particles is passed through a plurality of apertures simultaneously or consecutively or in consecutive groups, each aperture having its own aperture current supply and its own detector to provide one channel for the signals produced by the respective aperture.
  • Certain advantages are gained by the use of multiple apertures, such as savings of time, better statistical data, etc. Such advantages are inherent in this invention as well.
  • the apparatus of the first copending application includes a vote circuit which identifies and can reject automatically, information derived from a channel which is erroneous because of blockage of the aperture producing the signals-of that channel.
  • the disclosed embodiment of this invention uses such vote circuits, but, as will be seen, a feature of the invention substantially decreases, if not completely eliminates the need for such circuits.
  • the structure of this invention is of the special kind that uses apertures of different size to give statistical information of the distribution of particles in a system having particles of widely different sizes. Since this is a special case of the basic concept, a discussion of the problems involved in obtaining distribution data for this kind of a system will be in order, although to some small extent repetitious of the discussion in the first copending application.
  • the second copending application describes means for reducing particle count information gathered from a plurality of channels, all coupled to the single aperture of the apparatus.
  • the characteristics of an ordinary so-called industrial system of particles are fairly well known. These systems would include slurries,'dusts, powders, emulsions, and the like of a vast gamut of materials. These characteristics are generally as follows:
  • the dynamic range of particle size is very great, compared, for example with ordinary blood cells or biological particles.
  • the smaller particles not uncommonly, may be thousands of times smaller than the larger particles.
  • the occurrence of the particles, that is their distribution sizewise in the sample follows a general pattern in which there are an exceedingly larger number of smaller particles than larger particles For example, there may be tens of millions of particles of the order of several microns in diameter compared to a few hundreds of particles of the order of several hundred microns in diameter.
  • each pulse is equal to the duration of the particles stay in the aperture, and if operating conditions are properly chosen, the amplitude is proportional to the total volume of the particle, substantially irrespective of its shape.
  • optical scanning which responds to maximum cross sectional area of the particle perpendicular to the direction of light, which varies widely for irregularly shaped particles due to their unpredictable orientation.
  • Two characteristic curves are used to express particle distribution in the classical form.
  • One curve called the differential curve consists of a plot of the distribution of particulate material in the various ranges, the horizontal axis being particle size and the vertical axis being, volume of particulate material existing in any given range of particle sizes.
  • the second curve called the integral curve, gives percentage of particulate material above a stated size.
  • the horizontal axis of the integral curve is also particle size, but the vertical axis is volume or percent of the total mass of particulate material above any size.
  • the differential curve is usually somewhat bell-shaped, while the integral curve is a reverse S. Obviously, the percent point at the top of the integral curve will represent the smallest particle, and the 0 percent point of the same curve will represent the largest particle. In both cases, since the size range of particles is great the horizontal axis is usually logarithmic. One curve may also be converted into the other.
  • the invention contemplates a vastly increased use of the capabilities of an apparatus which operates on the Coulter principle as a result of which many advantages are achieved not capable of achievement heretofore.
  • Prior counting and sizing apparatus of the Coulter type utilized a single aperture for obtaining the information needed to describe a particle system. It was desired to extend the range of particle sizes covered by the aperture to derive as much information as possible from the aperture. Various techniques attended such attempts, all of which were directed toward the obtaining of the best quality and the maximum amount of information.
  • obtaining a saving of time in running a sample eliminating the problems involved in scalping or diluting; making unnecessary prior knowledge of the distribution and population of the type of particle system being studied; obtaining a vast increase in accuracy and in'the quantity of data which may be obtained on a given sample run; improving the reliability of the apparatus and in addition decreasing the likelihood of blockage; making possible the acquisition of valid data even when a blockage occurs; and in general improving greatly the overall quality and statistics in practically every respect of the information obtained.
  • one device described in said second copending application provided structure for reducing the data before presentation, so that the output of the device enabled the construction of the integral and differential curves of the particle system directly from the readouts.
  • a plotter suitably connected could draw the curves.
  • This apparatus used a single aperture to make a sample run, the spectrum of particle sizes being divided into a plurality of consecutive ranges each providing the signals to a separate channel by means of suitable threshold circuits.
  • the ranges were chosen to have a progressive relationship in accordance with a known function, such as, for example, a two-to-one relationship between contiguous ranges based upon the average size of the particles in the respective ranges.
  • An equal volume of suspension was scanned for each range in any given sample run.
  • the resulting counts were operatedupon before deriving the final data, in accordance with a progressive function equal to that used to divide the spectrum into ranges.
  • the values in the resulting series were directly proportional to the total volume of particulate material in each respective range.
  • the invention has as another object the provision of apparatus intowhich one may readily construct the principles of the data reduction structure described above, without unduly complicating the apparatus.
  • the invention provides output information for each channel in the form of a voltage which is proportional to volume per unit time, representing volume of particulate material in that channel or of that size particle, but considering the entire particle system. Thus the points of the integral curve are obtained directly. Since this information is being produced at all times, even when blockage occurs, the information obtained up to that time on any group of channels produced by the aperture which just blocked is still valid, albeit statistically representative only of the amount of sample scanned.
  • the structure of the invention accomplishes the above by using two elements in each channel controlled from the same voltage reference source.
  • One element furnishes volume information and the other time.
  • the volume information is provided by integrators that are slowly accumulating charge through capacitive pump circuits driven by the particle pulses.
  • a scale factor is applied to the pump circuits by the voltage reference source and size of pump capacitors.
  • the time information is obtained from an integrator which runs continuously and accumulates charge from the same reference voltage source. Signals from both integrators of each channel are applied to a multiplier, but the time integrator signal is first operated upon by a reciprocal computer so that the multiplier output is of voltage representing particle volume relative to time. Since the flow rate through each aperture is known, the multiplier output may be calibrated in terms of number of particles per unit volume of sample suspension which is the required form.
  • FIG. 1A and FIG. 1B are the left and right halves, respectively, of a block diagram of a portion of a particle analyzing apparatus constructed in accordance with the invention, the portion illustrated relating only to the channels of one of a plurality of apertures included in the apparatus.
  • FIG. 2 is a placement diagram showing the relationship between FIGS. 1A and 1B.
  • FIG. 3 is a front elevational view of a structure which may be used to provide the scanning system for the entire apparatus, including means for functionally supporting six apertures.
  • FIG. 4 is a sectional view taken through the structure of FIG. 3 along the line 4-4 and generally in the indicated direction.
  • FIG. 5 is a diagram of a typical pump circuit of thetype used in the apparatus.
  • FIG. 6 is an enlarged sectional view along the line 6-6 of FIG. 4.
  • the apparatus of the invention utilizes a plurality of apertures, each of which is chosen according to a sequence designed to use a high degree of the capabilities of the aperture, considering sensitivity, coincidence, flow rate and the probability of clogging.
  • the apertures may be mounted in a plurality of aperture tubes of the type known and all tubes immersed in a container of the sample for a static determination, or these apertures may be located in a conduit or pipe through which there is flowing a continuous stream of the sample suspension. In either case, the structures may take many dif ferent forms. One such form is shown in FIGS. 3 and 4.
  • Each aperture is connected into the system in a manner to provide independent flow-including means to permit the sample to be carried through the apertures consecutively or simultaneously or in consecutive groups. Means may be provided to trigger the operation of one flow inducing means upon the completion of operation of the preceding one.
  • Each aperture has an independent current source and an independent detector, such that care must be taken electrically to isolate the downstream ends of the apertures to prevent interaction between them. There will be an electrode in the downstream fluid for each aperture and a single common electrode in the upstream body of fluid, usually at ground potential.
  • the flow time in heavily populated ranges may be decreased by any suitable factor to give a count which may be then multiplied by the factor to give the total relative count. This decreases the chance of clogging by the same percentage. Furthermore, since there is to be an operation made upon the count to provide the desired data reduction, such operation could as easily be fonned by means of changing the time for the sample flow, either alone or in combination with some other means.
  • the apparatus through the use of multiple apertures, may utilize rate of flow, size of aperture, and in addition, variation of constants of the circuits to achieve the desired operation upon count, and hence in this respect alone, is a substantial improvement upon the prior single aperture apparatus. In addition, the need for scalping and redilution is eliminated.
  • the particular apparatus which is discussed herein is one in which there is a plurality of channels for each aperture, so that the range represented by the chosen limits for any aperture may in turn be divided into what may be called subranges, each of which produces signals passing through a single electrical channel. Furthermore, means are included in the apparatus for taking only as much data as absolutely necessary including means for arriving at a correct measurement even if an aperture clogs, the latter event being less likely to occur in this apparatus than in previous devices.
  • aperture sizes and particle size ranges described above results in an important, unexpected, and previously overlooked benefit, namely, the ability to accept, without further adjustment or manipulation, particulate systems of any nature, whether broad or narrow, consisting mostly of large or small particles, that is, whether the bellshaped curve is broad or narrow at the center, whether the peak occurs right or left of center, and so on.
  • Suitable analog clock means are used to permit the apertures to pass fluid suspension for only the minimum time that it is almost certain a good sampling will be obtained while clogging is unlikely, considering that particular size of aperture.
  • the data reduction is performed in part by this decrease in sample as the particle size decreases. Even if clogging does occur, data which is taken may be divided by the elapsed time to make it usable, but perhaps with less statistical reliability.
  • FIGS. 1A and 13 actually comprise parts of a single illustration. This is intended to show a single range, defined by an aperture, and three subranges or channels within the principal range. As will be seen, from the numbering of the components, it is understood that this in turn is a small part of a large apparatus, but the components of the ap' paratus are repetitious in nature, the whole being designed to give a thorough statistical analysis of a particle system.
  • the block it) which is identified as A4! is one of six apertures, for example, which are used by the apparatus. Accordingly there are other blocks which would be displayed above the portion shown which represent the larger apertures, and which would be identified as Al, A2 and A3. Likewise, the portion below the illustrated portion would have blocks representing the smaller apertures identified as A5 and A6.
  • the sizes of the six apertures might be chosen as A1 560 microns in diameter A2 280 microns in diameter A3 microns in diameter A4 70 microns in diameter A5 30 microns in diameter A6 20 microns in diameter
  • These apertures each represent a range of particle sizes, and were chosen to afford the best statistical information in the ranges which will be covered by each.
  • the largest aperture, which would be A1 might be divided by suitable threshold circuits into nine subranges and thus provide information on nine channels; the next four ranges might each have three channels, and the smallest range might have four channels.
  • the channels for the extremes of size range typically include a very small percentage of the total particulate material and hence do not justify the accuracy obtained by having only three sized subranges per aperture. Thus, there would be a total of 25 channels provided by six apertures.
  • the apertures are chosen so that the diameters decrease from aperture to aperture by very nearly a factor of two.
  • the amount of sample which will be moved through the respective apertures will be equal in simple apparatus, but for best results should vary in accordance with the size of the particles studied.
  • the smaller apertures will be primarily used for obtaining the signals from small par ticles, which are typically extremely numerous, only a fraction of the amount of sample taken in the larger apertures will be driven through the smaller.
  • a structure for accomplishing this could be a micrometer head syringe operated by a constant speed synchronous motor.
  • the motor is clutched to the syringe by a high speed magnetic or other type of clutch, and a suitable timing device, such as a light interrupter disc with light source and photocell may give a digital or analog measurement of the amount of movement of the syringe, to be related in other parts of the-circuit with other components of the apparatus.
  • a suitable timing device such as a light interrupter disc with light source and photocell may give a digital or analog measurement of the amount of movement of the syringe, to be related in other parts of the-circuit with other components of the apparatus.
  • This fluid driving device whether operated by pump or suction may be the same for several apertures, those with greater sampling time and requiring passage of greater amounts of sampling fluid being associated with other fluid moving devices.
  • the fluid moving device is the block 11, called a suction device 04. Each aperture will have its own suction device.
  • the practical structure of FIGS. 3 and 4 does not illustrate fluid moving means. Some fluid moving means are illustrated in U.S. Pat. Nos. 2,869,078 and 3,015,775.
  • the aperture A4 like the others, has its own aperture current supply source identified by the designation R4 and the block 12.
  • the signal from the aperture A4 is amplified to a useful level by the amplifier 135 shown in block 13.
  • Output from the amplifier B5 is applied by way of the connections 14, 15, 16 and 17 to the blocks 18, 19, 20 and 21, respectively, these blocks being identified by the labels C16, C17, C18 and C19, respectively; and threshold levels are built into the blocks in such a manner that there is a factor of two between each threshold level all through the apparatus.
  • the threshold circuits between contiguous aperture groups have the identical level.
  • next threshold circuit above C16 which is the smallest in the group served by the aperture A3 and is shown in the drawings, is C15, identical in level to C16.
  • first threshold circuit C20 of the next smaller group is identical in level to the level of the threshold circuit C19.
  • Two types of Coulter electronic counting and sizing apparatus in use have different kinds of threshold circuits, one of which has a single voltage level to pass only pulses which exceed that level, and the other of which has two voltage levels, so that only pulses whose amplitudes fall within the defined window will be passed.
  • the first type of threshold circuit is an integral type
  • the second is a differential type.
  • a differential type typically comprises two integral types interconnected by veto logic circuitry. These kinds of threshold are both useful in accumulating and reducing data obtained by Coulter Counters as the Coulter apparatus is known.
  • the threshold circuits identified as C are of the integral type, hence there is one more threshold in each range than the number of eventual channels to define size limits. Ob viously differential threshold circuits could be used.
  • the threshold circuits throughout the apparatus are connected in pairs to veto logic circuits designated D.
  • the threshold circuits C16 and C17 are connected to the veto logic circuit D13.
  • the threshold circuits C17 and C18 are connected to the veto logic circuit D14.
  • the threshold circuits C18 and C19 are connected to the veto logic circuit D15.
  • the veto logic circuits are designated by reference characters 22, 23 and 24.
  • the veto logic circuits define the limits of channels by preventing any pulses whose amplitudes do not fall between the levels established by the two thresholds feeding each veto logic circuit from eliciting an output from a veto circuit.
  • each pair of threshold circuits and their connected veto logic circuit form a differential threshold circuit defining a window.
  • the outputs from the veto logic circuits appear at 25, 26 and 27 and must pass through the AND gates E13, E14 and E in order to affect the pump circuits F13, F14 and F15, respectively.
  • the AND gates are numbered 28, 29 and 30 while the corresponding pump circuits are numbered 31, 32 and 33.
  • the AND gates are opened and closed at various times by the signals appearing at the control line 34, and thus determine the times that pulses will be fed through the pump circuits to integrator circuits where they are accumulated. Integrator circuits are identified by the letter G and the blocks are numbered 35, 36 and 37. During a count, a voltage exists on the line 34 so that signals from the veto circuits D13, D14 and D15 will pass through the gates.
  • each pump circuit includes a capacitor which is to be charged upon the arrival of pulse via path 57, 58 or 59 to the voltage impressed on path 49 by DC reference 74 of FIG. 1B, the charge being pumped to the integrator connected to that pump circuit.
  • the amount of charge that any given pump circuit will transmit to its integrator for a given pulse is determined by the reference voltage derived from the line 49 and the capacitance of the capacitor. Reference may be had to FIG. 5 for an example of pump circuit.
  • the incoming pulses appear via the path 57, having been transmitted from one of the AND gates E13, E14 or E15.
  • Pulses operate a switch 181, which has the effect of connecting the capacitor 182 alternately between the reference voltage supply means K and ground. Each time the switch 181 connects capacitor 182 to the reference voltage K, it charges up to this voltage due to current flowing through diode 184. When the switch reverts to its normal position, the diode 184 blocks flow of current to ground and the diode 183 passes substantially all the charge to the integrator.
  • the switch 181 may be a transistorized circuit in which transistors are switched between conducting and nonconducting conditions upon receiving pulses from the AND circuit preceding.
  • integrators G13, G14 and G15 are each accumulating information which represents volume of particulate matter for each channel.
  • the current supply R4 at 12 and the fluid moving device Q4 at 11 have connections to a control binary circuit P9 which is shown at 39 on the left-hand side of FIG. 1A.
  • This latter circuit is usually in the form of a set-reset flip-flop (or RS flipfiop) whose purpose is to start and stop the counting of the entire range defined by the channels of A4.
  • This same circuitry is duplicated for each aperture.
  • counting in the several ranges may be done simultaneously for all apertures, consecutively, or in groups.
  • the line 40 originates in a suitable common control for all control binaries connected to the apertures, which may manually or electrically furnish a start signal to all aperture scanning systems. If consecutive, either individually or in groups, the signal may come as a result of some prior event. In this embodiment, the start signal comes from the completion of counting in the previous contiguous range.
  • the control binary P2 shown as block 62 at the bottom of FIG. 1A is equivalent to the binary P3.
  • This line 64 connects with the line 40 through a trailing edge detector 66 which connects with the control binary P9 so that the state of this binary is changed.
  • the scanning is started by this change of state of the binary P9 and likewise it produces a signal output 42 passing through the delay circuit S3 at 44 and the line 43 to the control binary P3,
  • the delay circuit P3 is to obviate switching transients caused by starting the scanning operation.
  • the change of state of the control binary P3 places a signal on the line 3d and its extensions, thereby providing one input to the AND gates E13, E14, E15 and E23 at 77 in FIG. 113, so that these gates are receptive to signals. Otherwise, no signals can pass these gates.
  • the voltage on the line 34 does not affect the control binary P at 101 of the next range until it is removed by control binary P3, at which time the trailing edge detector 103 applies the necessary trigger to initiate the same cycle of events in the next range.
  • the signal at 65 changes the state of binary control circuit P3, removing the voltage on the line 34 and its extensions and blocking the AND gates 28, 29 and 30. It also changes the state of the control binary P10, shown in block 101 and this starts the counting in the next channel.
  • the count in the channels of aperture A4 will continue until some predetermined number of particles is counted on one of the channels of the aperture Ad, unless halted prematurely by approaching saturation of any integrator by OR gate J10 and threshold circuit C40 or at a predetermined time as set by threshold C io, or upon the arrival of a pulse via line 67 indicating a pluggage.
  • This number of particles is controlled by the threshold circuit C33 shown in FIG. 18 at 46.
  • This' threshold circuit when operated by reaching the proper number which has been set into its circuit, that is voltage, produces a trigger signal at 47 that is applied to the OR gate J4.
  • the outputs from this gate are 65 and 41.
  • Output 65 triggers binary P3 as explained above.
  • Output d1 triggers control binary circuit P9 which stops the operation of scanning.
  • the size of the integrator capacitors and the size of the pump capacitors in the pump circuits F13, F14 and F are adjusted to be proportional to the volumes of the particles represented by each channel, the information stored in the integrators G13, G14 and G15 is proportional to the volume of material in that size range. This information is continually passed to readout circuits, as will be described, by suitable connections 83, 84 and 85.
  • the integrator 615 has its output 52 connected to the OR gate J33
  • the integrator G14 has one output 53 connected through the voltage divider H7 to the line 5% which leads to the input of the OR gate J33
  • the integrator G13 has its output 55 going through the voltage divider 1-16 to the line 56 which is another input ofthe OR gate J33. This latter is numbered 60.
  • OR gates comprise as many diodes as they have inputs and have the same circuit diagram as OR gates
  • their function is somewhat different from the function generally delegated to OR gates.
  • These circuits make use of the fact that the output voltage of an OR gate will equal the largest input voltage. It is thus an analog as well as a logical element. Accordingly, any one of the channels in the range may raise the voltage at 61 to a value which will reach or exceed the threshold level in the circuit C33. When this occurs the count is shut off in the manner described through the OR gate J4. J4 performs a logical function only. Note that any of the inputs to the OR gate J ll will shut off the count.
  • the debris alarm T4 may detect low frequency components caused by the presence of debris to give an audible or visual warning and a signal which shuts off the counting.
  • the threshold circuit C40 at 69 may be adjusted to some level which represents a condition just short of saturation of the circuit components connected to the inputs 70, 71 and 72 of the OR gate J10 and which will serve to stop the counting.
  • the path 73 to the OR gate M is provided with the separate, adjustable threshold circuit C46 at 99 in order to give the operator control over the counting time.
  • the threshold circuit C33 like all of the other threshold circuits in the apparatus is variable over a substantial range, such as for example 8] to l, which provides a 9 to 1 choice ofsigma which could be selectable by a suitable control on the threshold circuit.
  • this timing device is in the form of a simple integrator or clock integrator G28, shown in FIG. 113 at 76.
  • This integrator accumulates charge only from one source, namely the DC reference K by way of the line 75 and the switch E23, shown at 77. Since the switch E23 and the AND gates E13, E14 and E15 are all operated by the same control binary P3 via path 34, they all operate for the identical time interval and hence the voltage to which the clock integrator G28 charges is a measure of the time during which range particulate volume accumulations are made in the integrators G13, GM, and G15.
  • the DC reference K serves all of the pump circuits and clock integrators of the apparatus through lines 49 and 75.
  • the voltage from the clock integrator G23 is transmitted through a reciprocal computer L I shown at 79 to each of the multipliers M13, M14 and M15 designated by the characters 80, 81 and 82. Since the volume information from the integrators G13, G14 and G15 is also being transmitted to the multipliers by the lines 83, 5M and 85, respectively, the operation performed in each multiplier is to combine the voltage representing volume for a particular channel and the reciprocal of time. The result is volume per unit time. Since the flow rate through each aperture is known, this is directly convertible to particulate volume per size range per unit volume of suspension.
  • This output at 89, 911 and 91 is the desired information which is always valid, irrespective of how much sample has passed through the aperture and for how long. Accordingly, stopping the pulses from the aperture A l at any time before the desired count is reached will not affect the information gathered up to that time. The only question will be the statistical quality.
  • the voltage of the source could be variable from a low valuesay 12.5 volts to 200 volts and this could be related to values of sigma. Low voltages would establish small unit charges and cause the volume integrators to accumulate charge at a slow speed thereby permitting the storage of many times more unit charges than if the reference voltage were high, before saturating. The clock integrator would also be slowed down. As indicated, the relationship would not change,
  • the reciprocal computer L4 at 79 transmits the signal from the clock integrator to all multipliers 80, 81 and 82.
  • the multipliers are accordingly performing the operation particle count multiplied by relative cubic volume divided by time.
  • This quantity is fed by the read-outs N13, N14 and N15, shown respectively at 86, 87 and 88. It may be described as the mean particle volume multiplied by the particle count in each channel per unit time. Since time is proportional to the amount of sample volume passed, this yields as an expression which may be written k(pv) (pc)/sample volume total particle volume per channel/sample volume where k is some constant, pv, is the means particle volume of the channel in question and pc is the particle count per channel.
  • the voltage output at 89, 90 and 91 represent these quantities. These quantities may be fed by suitable lines to a summing matrix 92 along with the other values from the other channels, the output used to draw a curve in a suitable plotter 93 giving directly percent above stated size, or any other curve representing the values.
  • each line at 89, 90 and 91 carries a voltage which is proportional to the volume of material in the window represented by that channel or subrange of the range encompassed by the aperture A4, the information which has been achieved is the ultimate desired by the particle worker to use in the construction of his classical curves.
  • the apparatus has weighted everything in accordance with the time run, size, and so on, having performed all of the data reduction required to give volume of particulate material for the particular size of particles in that range.
  • FIGS. 3 and 4 With respect to the scanning system, one form of multiple aperture apparatus using six apertures is shown in FIGS. 3 and 4.
  • the apparatus is designated generally 120 and is shown as apparatus for use with a static sample, but it should be understood that it is capable of being used with a flow-through or on-stream sample.
  • a vessel 121 which has a generally circular sidewall 122 with a rear wall 123 and a relatively thick front wall 124.
  • the vessel is preferably made of glass or other insulating material, and the purpose for making the front wall relatively thick is so that conical sockets may be accurately formed therein as by grinding.
  • Such a socket is shown at 125.
  • a female fitting 126 is mounted on the sidewall 122 in the bottom thereof for drainage, there being a suitable stopcock 127 engaged therein for obvious purposes.
  • This aperture is designated 128, and it is formed in a wafer 129 set into the bottom wall of a hollow, generally frustoconical fitting 130 that includes an outer cover glass 131 held in place by spring 132, and upper integral inlet conduit 133 and a lower outlet conduit 134.
  • this structure described in connection with the fitting 130 is duplicated in each of the other fittings 140, 141, 142, 143 and 144.
  • The-purpose of the inlet conduit equivalent to the conduit 133 shown in H6. 4 is to enable fluid to be introduced into the interior chamber of each of the fittings. This chamber is designated 145 in the fitting 130, and it is in contact with the electrode 135. Likewise all of the chambers have this same arrangement.
  • each fitting has its own electrode equivalent to the electrode 135 and its own hot electrical lead. These are designated 147, 137, 148, 149, 150 and 151.
  • the common electrode 152 in the vessel 121 has an electrical lead 153 common to all the other electrical leads.
  • the construction using the disclike cover glasses, as shown in 131, enables the inner chambers to be cleaned and enables the ready installation, repair, etc., of the electrode system. It also enables illumination and viewing of the apertures, as by elements 154 and 156.
  • Apparatus which utilizes more than three or four apertures would most likely be used in distribution studies so that the aperture sizes would be different. in such an arrangement it would be preferable that some advantage be taken of the tendency of the larger particles to settle. Statistically, this would not to any great extent change the nature of the distribution data if settlement were not permitted to take place over a substantial period of time. Accordingly, it would be preferred that the aperture of the fitting 144 be the smallest and the aperture of the fitting 140 be the largest with the intermediate graduated. The order of increasing size would be in accordance with the level of the aperture and would be 144, 142, 130, 143, 141, 140.
  • a large drain at the bottom of the vessel could permit large and heavy particles to drop into the fitting 126 where they could remain despite efforts to stir the suspension, and upset the true size distribution.
  • a poppet valve is seated in the seat 171 formed in the vessel when the stopcock is closed (FIG. 6).
  • the plug 172 has a groove 173 which cooperates with the valve stem 174 to permit the valve 170 to drop into seated condition when the stopcock is closed. When the plug 172 is rotated to open condition the valve is raised.
  • the illustrated apparatus and description omit any reference to a voting circuit which could act to stop the operation of that portion of the apparatus which includes an aperture that clogs. if desired, this could be connected using contiguous channels in different ranges as the comparison basis. Since these channels are preferably of the same range of size, the result is common ranges in different apertures which may be used in connection with differential amplifiers to produce signals when different, indicating an abnormality in at least one of the apertures.
  • a method for analyzing a particulate system by the use of at least one passageway through which a sample portion of the particulate system passes and is detected comprising the steps of:
  • a method according to claim 1 comprising the further step of dividing the volume of said sample portion by said specific time
  • a method according to claim 2 comprising the further step of maintaining the ratio between sample portion volume and specific time constant.
  • a method according to claim 3 comprising the further steps of terminating the accumulating step upon the accumulation of a preset signal amplitude in one of said channels.
  • a method according to claim 3 comprising the further step of terminating the duration of said specific time in response to improper detection of said particles.
  • a method according to claim 3, comprising the further step of terminating the duration of said specific time in response to an accumulation of said output signals upon attaining signal capacity of any one channel.
  • a method according to claim 3 comprising the further step of terminating the duration of said specific time in response to a fixed time measurement.
  • a method including sending the output signals through a plurality of the passageways arranged logically parallel, each passageway arranged to pass the separated output signals through its interrelated channels, and
  • a method according to claim 8 comprising the further step of enabling said accumulating step for the separated output signals for any one of said plurality of channels in relationship to the same accumulating enabling of the other of said plurality of channels.
  • a method according to claim 8 comprising the further step of regulating the rate of flow of said sample portion through said passageways so that such rate is different for each passageway.
  • a method according to claim ti comprising the further step of arranging the passing of the output signals through the passageways such that a narrow amplitude range is sent through each passageway.
  • a method according to claim d comprising the further step of summing progressively said product in each channel for all said channels.
  • Apparatus for analyzing particles suspended in a fluid medium which comprises:
  • each aperture being a different size
  • transducer means associated with each aperture to produce signals as particles pass therethrough, said signals being respectively proportional to particle volume
  • threshold circuit means dividing each transducer output into a plurality of size channels, each channel having means for accumulating charge proportional to total particulate volume and deriving a first signal proportional to said accumulated charge,
  • Apparatus according to claim 14 in which means are provided to render said fluid moving means operative for each aperture consecutively.
  • Apparatus according to claim M in which means are provided to disable all of the channels associated with any aperture after a predetermined length of time so that the duration of signal transducing associated with each aperture varies directly as the size of the aperture.
  • Apparatus according to claim 14 in which disabling circuits are provided for disabling the operation of any given group of channels associated with an aperture when the aperture has passed a number of particles which produce charge accumulation to :a predetermined signal level in any one ofa plurality of circuits, including at least said charge accumulating means.
  • Apparatus according to claim M in which the aperture sizes vary from aperture to aperture by a factor, and
  • the size ranges of the channels associated with each aperture also vary by the same factor.
  • the channel size ranges progress from aperture to aperture.
  • Apparatus according to claim M in which said aperture sizes differ by a factor which causes the percentage of coincident passage of particles of the smallest size measured by each aperture to be substantially the same for all apertures, such that the same particle concentration can be effectively scanned by all apertures, substantially irrespective of the breadth and average size of the particle system.
  • the size ranges of the channels associated with each aperture vary by a factor of substantially two to one by particle volume.
  • an inverse time signal accumulating circuit comprises said second signal deriving means
  • a reference voltage is connected to said pump circuit and said time signal accumulating circuit so that the rate of charge accumulating and time signal accumulating are always inversely proportional to each other, and
  • multiplying means connects each charge accumulating means with said time signal accumulating circuit to define said dividing means and provides an output signal representative of particle volume per unit concentration irrespective of the amount of time that the aperture is passing fluid medium.
  • Apparatus according to claim 23 further comprising means for dividing the volume of said sample portion by said specific time, thereby yielding the ratio of total particulate volume per channel to volume of said sample portion.
  • Apparatus according to claim 24 further comprising a reference signal source coupled to said accumulating means and said generating means for maintaining the relationship between sample portion volume and specific time constant.
  • Apparatus according to claim 25 further comprising means for terminating the duration of said specific time in response to a preset signal amplitude in one of said channels.
  • Apparatus according to claim 25 further comprising means for terminating the duration of said specific time in response to improper detection of said particles.
  • Apparatus according to claim 25 further comprising means for terminating the duration of said specific time in response to an accumulation of said input signals upon at taining signal capacity of any one channel.
  • Apparatus according to claim 25 further comprising means for terminating the duration of said specific time in response to a fixed time measurement.
  • Apparatus according to claim 23 in which a plurality of the passageways are arranged logically parallel, each having its interrelated channels, and
  • the incrementation of said channels is interrelated in a regular progression base upon particle volume.
  • Apparatus according to claim 30 further comprising means for enabling said accumulating means for said plurality of channels of any one passageway in times relationship to the enabling of said accumulating means for said plurality of channels of at least one other of said passageways.
  • Apparatus according to claim 30 further comprising means for regulating the rate of flow of said said sample portion through said passageways so that such rate is different for each passageway.
  • Apparatus according to claim 33 in which there is provided a sufficient plurality of passageways and channels per passageway for causing each passageway to respond to an especially narrow range of different volumes.
  • Apparatus according to claim 30 further comprising means for summing progressively said product in each channel for all said channels.

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US823743A 1969-05-12 1969-05-12 Particle analyzing method and apparatus employing multiple apertures and multiple channels per aperture Expired - Lifetime US3603875A (en)

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Cited By (10)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3768084A (en) * 1972-07-14 1973-10-23 Becton Dickinson Co Particle counter having a clog and bubble alarm
US3810011A (en) * 1970-05-25 1974-05-07 Coulter Electronics Apparatus and method for analyzing the particle volume distribution for a plurality of particles of different size in a quantity of liquid
US3863056A (en) * 1973-06-29 1975-01-28 Coulter Electronics Method and apparatus for multichannel voting
US4075462A (en) * 1975-01-08 1978-02-21 William Guy Rowe Particle analyzer apparatus employing light-sensitive electronic detector array
US4418313A (en) * 1976-02-24 1983-11-29 Medicor Muvek Process and circuit arrangement for the determination in a diluted blood sample of the number of red blood corpuscles, the mean cell volume, the value of haematocrit and other blood parameters
US4535284A (en) * 1981-07-10 1985-08-13 Coulter Electronics, Inc. High and low frequency analysis of osmotic stress of cells
US6175227B1 (en) 1997-07-03 2001-01-16 Coulter International Corp. Potential-sensing method and apparatus for sensing and characterizing particles by the Coulter principle
US20050218909A1 (en) * 2004-03-31 2005-10-06 Government Of The United States Of America As Represented By The Secretary Of The Navy Device to detect and measure the concentration and characterization of airborne conductive or dielectric particles
US20050285604A1 (en) * 2004-06-29 2005-12-29 Ryoichi Shinohara Partial discharge detecting sensor and gas insulated electric apparatus provided with a partial discharge detecting sensor
WO2010124202A1 (en) * 2009-04-24 2010-10-28 Beckman Coulter, Inc. Method of characterizing particles

Families Citing this family (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE3227664A1 (de) * 1982-07-23 1984-02-02 Vladimir Vasil'evič Saratov Pavlov Einrichtung zur messung der menge und groesse fester teilchen in fluessigen und gasmedien
EP0100891A1 (de) * 1982-08-17 1984-02-22 Contraves Ag Verfahren und Vorrichtung zur Korrektur von Koinzidenzfehlern beim Zählen von Teilchen zweier Sorten
US9124769B2 (en) 2008-10-31 2015-09-01 The Nielsen Company (Us), Llc Methods and apparatus to verify presentation of media content

Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3331950A (en) * 1966-07-11 1967-07-18 Coulter Electronics Particle distribution plotting apparatus
US3345502A (en) * 1964-08-14 1967-10-03 Robert H Berg Pulse analyzer computer

Patent Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3345502A (en) * 1964-08-14 1967-10-03 Robert H Berg Pulse analyzer computer
US3331950A (en) * 1966-07-11 1967-07-18 Coulter Electronics Particle distribution plotting apparatus

Cited By (11)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3810011A (en) * 1970-05-25 1974-05-07 Coulter Electronics Apparatus and method for analyzing the particle volume distribution for a plurality of particles of different size in a quantity of liquid
US3768084A (en) * 1972-07-14 1973-10-23 Becton Dickinson Co Particle counter having a clog and bubble alarm
US3863056A (en) * 1973-06-29 1975-01-28 Coulter Electronics Method and apparatus for multichannel voting
US4075462A (en) * 1975-01-08 1978-02-21 William Guy Rowe Particle analyzer apparatus employing light-sensitive electronic detector array
US4418313A (en) * 1976-02-24 1983-11-29 Medicor Muvek Process and circuit arrangement for the determination in a diluted blood sample of the number of red blood corpuscles, the mean cell volume, the value of haematocrit and other blood parameters
US4535284A (en) * 1981-07-10 1985-08-13 Coulter Electronics, Inc. High and low frequency analysis of osmotic stress of cells
US6175227B1 (en) 1997-07-03 2001-01-16 Coulter International Corp. Potential-sensing method and apparatus for sensing and characterizing particles by the Coulter principle
US20050218909A1 (en) * 2004-03-31 2005-10-06 Government Of The United States Of America As Represented By The Secretary Of The Navy Device to detect and measure the concentration and characterization of airborne conductive or dielectric particles
US7034549B2 (en) * 2004-03-31 2006-04-25 The United States Of America As Represented By The Secretary Of The Navy Device to detect and measure the concentration and characterization of airborne conductive or dielectric particles
US20050285604A1 (en) * 2004-06-29 2005-12-29 Ryoichi Shinohara Partial discharge detecting sensor and gas insulated electric apparatus provided with a partial discharge detecting sensor
WO2010124202A1 (en) * 2009-04-24 2010-10-28 Beckman Coulter, Inc. Method of characterizing particles

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NL153330B (nl) 1977-05-16
JPS5327639B1 (de) 1978-08-09
IL34489A0 (en) 1970-07-19
SE358471B (de) 1973-07-30
DE2022878B2 (de) 1975-01-16
IT942505B (it) 1973-04-02
DE2022878A1 (de) 1970-11-19
IL34489A (en) 1973-01-30
FR2047580A5 (de) 1971-03-12
GB1311213A (en) 1973-03-28
NL7006782A (de) 1970-11-16
DE2022878C3 (de) 1975-09-04

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