FI68911B - FAERGPYROMETER - Google Patents

Description

[«Sr ^ l FBI (11) SHOOTING PUBLISH, SU ÄÖQ11 l J 'UTLÄGGN, NGSSKR, IFT uo 7 Ί 1 • Jjgg C (45) Fato-: ti -yvJr.natly 11 11 1935 (51) Kv.lk.4 /lnt.CI.4 G 01 J 5/60 SUO MI— "FI N LAN D (21) P» tenttlh »kemus - Patentansökrtlng 772907 (22) HakemlspWv» - Antöknlngtdag 03.10.77 (FI) (23) Alkupilv »- Giltlghetsdag 03.10.77 (41) Became public - Bllvlt offentllg 04.04.79

National Board of Patents and Registration NShtSviksipanon j. kuui.julkai.un pvm. _ ,, „fic

Patent-och registrstyrelsen v 'Ansökan utlagd oeh utl.skrlften publlcerad 31.U / .Ö5 (32) (33) (31) Requested Privilege - Begird prlorltet (71) (72) Dmi try Evgenievich Egorov, ulitsa Alexandra Nevskogo, 10, kv. 37, Leningrad, Vladimir Tikhonovich Negrutsak, Vasilievsky Ostrov, 6 lines 5/5, kv. 4, Leningrad, Sergei Pavlovich Syrtsov, ulitsa Mayakovskogo 59, kv. 11, Pushkin, Leningrad Oblast, USSR (SU) (74) Oy Kolster Ab (5 * 0 Color Pyrometer - FSrgpyrometer This invention relates to devices for measuring temperature and in particular to color pyrometers.

The present invention is most preferably used for non-contact temperature measurement of an optically radiating body in high speed cold or hot rolling processes of metal, as well as in high speed welding.

A measuring device for measuring color temperature is already known in the current state of the art (cf. e.g. British Patent No. 1,265,417). This measuring device determines the color temperature of a hot and optically radiating body, it means the temperature at which a black body is the same color as a detected radiating body by measuring the amount of radiant energy in two different wavelength ranges of the radiation emitted by the radiator and determining this ratio photovoltaically. Thus, in the process, the irradiance of the detected radiating body is thus determined by means of suitable attenuator portions, e.g. an iris dimmer, which that ratio and, consequently, is a measure of the color temperature of the detectable radiating body. This color temperature measuring device includes an optical system for applying a narrow beam of the radiation emitted by the object to be measured, an adjustable attenuator positioned in the optical beam path to attenuate that optical beam, a beam splitter locally dividing the beam obtained from the two adjustable attenuators into two partial beams, radiation from a different wavelength range from the amount of radiation emitted from the detected body, narrowband color filters for filtering radiation from different wavelength ranges separately from each of the partial optical beams. The known color temperature measuring device is further provided with two photoelectric devices for detecting different wavelength ranges of the radiation separated by the radiation filters and providing electrical signals which are proportional to the radiation intensities in those wavelength ranges. In addition, this known device includes an electrical signal attenuation channel that reduces the electrical signal generated by one of said photovoltaic devices, which is proportional to the intensity of the radiation in one of said wavelength ranges, converting it to a predetermined value. This channel includes a comparator having a pulse-like reference source and an amplifier for comparing the above-mentioned electrical signal to a specific reference pulse, and a servo system connected to this comparator having an amplifier-controlled electric motor for adjusting the adjustable attenuator. This previously known measuring device also includes a channel for measuring the electrical signal produced by the second photoelectric device, this signal being proportional to the radiation intensity in the second wavelength range, this channel also including an amplifier for amplifying this signal according to the color temperature of the object to be measured.

i 3 6891 1 The main disadvantage of this color temperature measuring device is its slow response speed, which is determined by the high time delay of the defined servo system and in turn the inertia characteristics in the drive motor and mechanical attenuator, which attenuates the undivided optical beam. This time delay of the servo system causes random signals to appear at the output of the color pyrometer when there are rapid changes in the intensity of the radiation emanating from that object and immediately immediately after the appearance of this object in the field of view of the measuring device.

In addition, the previously known color temperature measuring device suffers from a complex structure derived from the mechanical damper part used in it and controlled by a servo system which includes electromechanical parts. This results in poor device reliability.

Moreover, in the known device it is critical to guarantee the exact parallelism of the rays which hit the attenuator in order to provide identity for radiation attenuation of different wavelength ranges, which is necessary to achieve high dimensional accuracy, as well as to ensure exact parallelism of the axes of the optical parts. uniform optical beam density in its cross-sectional plane.

The main object of the present invention is to provide a high velocity response to a color pyrometer measuring the color temperature of heated radiating bodies in at least two different wavelength ranges of radiation from this object.

This primary purpose is accomplished by providing a color pyrometer that includes an optical device that aligns a narrow optical radiation beam from the radiation emitted by the body whose temperature is now to be measured, a beam splitter equipped with color filters, which is then used to divide the beam. from an optical device to a partial beam and to filter out radiation having different wavelength ranges from those partial optical beams; a certain second electrical signal to a predetermined value, this electrical signal being formed in one of the photoelectric devices and being proportional to the intensity of the radiation in the other of the waveguide ranges in question, this channel including an amplifier for amplifying the electrical signal and a comparator including a reference pulse input source for comparing said electrical signal to the reference pulse, and having at least one channel for measuring an electrical signal generated by another photoelectric device proportional to the radiation intensity at the other wavelength range; this comprising an amplifier for amplifying this electrical signal and wherein according to the present invention each of the channels is provided with matching parts for matching the electrical parameters of the photoelectric devices connected to the input of this matching part with the electrical characteristics of the adjustable distributor, the distributor consisting of a resistor and an adjustable resistor being connected to the output of the matching part, while the output is connected to the input of the amplifier, from which the delay part is connected to the attenuation channel, k and the measuring channel is provided with an electronic switch, the output of the attenuator channel amplifier being converted to the input of its comparator, the output of which is connected to the inputs of the adjustable resistor type parts of the adjustable dividers on each channel and

Such an arrangement of the proposed color pyrometer ensures a sharp reduction in the amount of crossing of the output mark by the pyrometer in response to a rapid change in the intensity of the radiation emitted by the detected object at the moment immediately following the appearance of the object in the pyrometer's field of view. This reduction is realized by the inclusion of an electronic switch in the pyrometer circuit, and this switch initially bypasses the measuring channel for the time determined by the delay device, thus substantially reducing the time required to set the average output signal and increase the response speed of this pyrometer.

It is preferred that the adjustable resistance-type parts for both attenuation and the measuring channel be made as a single integrated circuit, each adjusted resistance-type part including a transistor from which its control electrode is connected to the comparator output, one of its output electrodes connected to the resistor of the corresponding adjustable distributor to the common point of the variable distribution devices.

The adjustable resistance-type parts, which are provided as a single integrated circuit, provide a high degree of similarity to each other, which guarantees a high dimensional accuracy for the proposed color pyrometer.

The invention will now be described in more detail by means of exemplary cases with reference to the accompanying drawings.

Figure 1 is a block diagram of a color pyrometer in accordance with the present invention.

Figure 2 is an electrical circuit of a controlled resistor type according to the present invention.

The color pyrometer includes an optical system and an electrical circuit. The optical system includes an optical device in the form of a lens 1 (Fig. 1) for directing the radiation emitted by the object to be measured (not shown) into a narrow optical beam 2. The modulator 3 for modulating the optical beam 3 is in fact an electromechanical generator and is provided with a part which performs mechanical vibrations, this part being located in the path of the optical beam 2 between the lens 1 and the beam splitter 5, the latter being associated with narrowband color filters. not shown). The beam splitter 5 is used to divide the optical beam 2 into separate beams in a given state, each of these containing the wavelength regions of the radiation of the detected body, which regions differ from each other. This color pyrometer allows the common optical beam 2 to be divided into several separate optical beams, the number of which is determined solely for practical purposes. For the sake of simpler explanation, the beam splitter 5 shown in the figure divides the optical beam 2 into three separate beams 6, 7 and 8, which hit the photovoltaic devices, namely the semiconductor type photodiodes 9, 10 and 11, respectively.

The electrical circuit for the color pyrometer includes measuring channels 12 and 13 for measuring the electrical signals generated by the photodiodes 9 and 10, respectively, and an electrical signal attenuation channel 14 for attenuating the electrical signal generated by the photodiode 11 to a predetermined value. The measuring channels 12 and 13 and the devices forming their parts are completely similar to each other and operate completely analogously to each other, as a result the same reference numerals are used for the same components, so that only the measuring channel 13 will be described below. However, it should be remembered that the measuring channels 12 and 13 provide those different electrical signals which are proportional to the difference in the radiation of the body detected in the wavelength ranges.

The measuring channel 13 includes matching parts 15 which match the dynamic electrical parameters of the output of the photodiode 10 connected to the input of this matching part 15 to the electrical characteristics of the variable divider, which divider consists of a constant resistor 16 and an adjustable resistor type part 17 having a control input, and to the output of section 15.

The output of the adjustable divider is connected to the input of the amplifier-demodulator 18, from which the output is connected to the input of the normal soy 19. The output of said normalizer is connected to the output terminals 20 and 21 of the pyrometer and any suitable detector (not shown) is connected to these. The measuring channel 13 further comprises an electronic switch 22, the output of which is connected to the output of the matching parts 15.

The attenuation channel 14 of the electronic signal, attenuating the electrical signal generated by the photodiode 11 to a predetermined value, includes matching portions 23 for matching the dynamic electrical parameters of the output of the photodiode 11 to the electrical characteristics of the adjustable divider. 24 and an adjusted resistor type portion 25 with an adjustable input. The output of the adjustable and echo sounder is connected to the input of an amplifier demodulator 26, from which the output is connected to one of the inputs of the comparator 27. A second pulse input source 28 is connected to the second input of the comparator 27. The output of the comparator 27 is connected to the input of a delay device 29, which consists of an integrating circuit 30 and a threshold device 31 connected in series therewith. The output of the delay device 29 is connected to the input of an electronic switch 22. to the output of the matching part 15 via the measuring channel 13. The output of the comparator 27 is also connected via adjustable resistors 32 and 33 to the adjustable inputs of the adjustable resistance parts 17 and 25 in the adjustable distributor device via the measuring channels 12 and 13 and the damping channel 14, respectively.

The proposed color pyrometer works as follows.

The radiation emitted by a given body, which body temperatures are to be measured (which body is not shown) is collimated by a lens 1 into a narrow contractable optical beam 2, which is modulated by an oscillating part 4 by an optical modulator 3 operating in the frequency range 100-1000 Hz and then divided by space and by a beam splitter 5 into separate optical beams 6, 7 and 8, so that the optical beam 8 containing one wavelength range of the detected body hits the photodiode 11, the optical beam 7 containing the radiation of this body of another wavelength range hits the photodiode 10, while the beam 6 includes yet another wavelength range from the radiation of this body and impinges on the photodiode 9. The photodiodes 9, 10 and 11 generate alternating current signals having a frequency equal to the operating frequency of the optical modulator 3, the amplitudes of the signals emitted by the photodiodes 9, 10 and 11 being proportional to their radiation intensity in different wavelength ranges present in separate optical beams 6, 7 and 8, respectively. Modulation of a common optical beam 2 is used to substantially reduce the effect of dark current of photodiodes 9, 10 and 11 on the proportionality factor and dependence stability between optical beam intensities and their electrical signal amplitudes. signs these photodiodes are developing.

The AC signals generated by the photodiode 10 are applied to the measuring channel 13 in the pyrometer and fed to the input of the matching part 15 on this channel. However, these signals do not go any further, because after the pyrometer is switched on and for some time after the object is in the field of view of the pyrometer, the electronic switch 22 connected to the output of the matching part 15 is open, thus bypassing the output of that matching part and not allowing these signals to enter. from the output of the matching part 15 to the other parts of the measuring channel 13.

The AC signals generated by the photodiode 11 are applied to the attenuation channel 14 of the electrical signal, which attenuates said electrical signals to a predetermined value, and is then fed to the input of the matching portion 23 on this channel. The output signals from the mating parts 23 are applied to the input of a variable divider consisting of a constant resistor 24 and an adjustable resistor type 25, this adjustable divider acting in the same way as the adjustable divider of the measuring channel 13 and attenuating electrical signals proportional to the radiation intensity of the object. The AC signals divided by an adjustable divider are applied to the input of an amplifier demo demulator 26, which demodulates and converts the modulated AC signals into DC signals. The DC signal from the output of the amplifier demodulator 26 is applied to one of the inputs of the comparator 27 and its magnitude is compared to the reference pulse applied to the second input of the comparator 27 from the reference pulse input source 28. If the amplitude of the demodulated DC signal is applied to one of the comparator 27 inputs to its second input, an output error signal is generated, this is compared to the output, and this error signal is applied simultaneously to both the delay device 29 and the variable divider parts on all channels.

The output signal provided by the comparator 27, which is fed to the variable dividers, is applied through the matching resistors 32 and 33 to the inputs of the resistor-type parts 17 and 25, respectively, thus changing the transmittance of all adjustable dividers simultaneously until the amplifier-demodulator 26 what is the output signal of the reference pulse input source 28. In this case, the characters input to the inputs of these divider parts from the matching parts 15 and 23 at the outputs of these divider parts decrease by exactly equal amounts.

The output signal from the comparator 27 fed to the delay sections 29 is applied to the input of the delay section integration circuit 30. The delay section 29 guarantees the signal delay by the amount of time determined by the parameters of the integration circuit 30, namely with a certain integration constant and corresponding to the amount of the transient time delay of the attenuation channel 19. The signal is delayed to prevent the development of a random signal at the output of the measuring channel 13, which is determined by the finite response time on the attenuation channel 14. When the signal reaches its steady state, a voltage difference develops at the output of the threshold circuit 31 and is applied to the electronic switch 22.

When the electronic switch 22 is switched off, it no longer bypasses the output of the matching part 15 from the measuring channel 13, as a result of which the alternating current signals generated by the photodiode 10 reach the input of the variable partition 15 from the output of this splitter to the input of the amplifier demodulator 18, the latter converting these modulated signals into DC signals and further feeding them to the input of the normalizer 19. The output signals from the normalizer 19 are then fed to the output of this pyrometer

Ion to the terminals 20 and 21. The normalizer 19 converts the DC signals applied to its inputs, which provide information about the color temperature of the detected object radiation in the corresponding wavelength range to a form suitable for subsequent indication of that temperature by a display device which can be connected to the output switches.

In the event that the radiation intensity decreases when measuring the color temperature of the body due to e.g. a sudden increase in the absorption capacity of the medium between the body and the device or when the object falls out of the pyrometer, the output signal of the amplifier demodulator 26 is less than the attenuation channel 14 magnitude, a signal is generated at the output of the comparator 27, the polarity of this signal being opposite to the polarity of the output signal, which is generated under normal conditions. When this occurs, an inhibitory signal is provided at the output of the threshold device 31 in the delay section 29, thus opening the electronic switch 22 and bypassing the matching portion 15 output from the measuring channel 13 and preventing characters from carrying the color 20 of the detected object from entering the output switch 21 of this color pyrometer.

In the general case, the response characteristics of the control for the adjusted resistance-type parts 17 and 25 used in the variable distribution devices by the measuring channels 12 and 13 and the damping channel 14 in the color pyrometer in question must be substantially identical to each other. This can be done, for example, by using precision-type linear potentiometers or by impedance matching load boxes equipped with a suitable drive part.

However, such potentiometers and impedance matching load boxes have disadvantages in terms of cost and complexity, nor are they able to provide the reliability of operation and the desired response rate for this device. As a result, the resistor-type components 17 and 25 provided in the proposed pyrometer are designed as integrated electronic adjustable resistors, which guarantees the desired identity and response rates to those components, and thus the more advanced the integrated circuit technology is capable of achieving greater identity and symmetry. .

The adjusted resistance-type parts 17 and 25, which are included in the variable divider parts in the measurement and attenuation channels in the proposed color pyrometer, are made as a single integrated circuit. Each of the resistor type parts 17 and 25 includes a bipolar transistor 34 (Fig. 2), from which a control electrode or base is connected to the output of the comparator 27 via a matching resistor 32 or 33, one of the output electrodes, namely the emitter, is connected to a constant resistor 16 or 24 in a corresponding adjustable distributor 13 or in the attenuation channel 14, while the collector is finally connected to a common point of the divider parts to be changed. The field effect transistor can be used as an electronically controlled resistance type component as well.

The advantage of the proposed color pyrometer is its high response rate, which is determined primarily by the relatively small time delay of the electronic components used in the device and secondly by the small control time constant in damping variable and echo cancellers of about 50 milliseconds at 400 Hz. The total response rate for the color pyrometer is about 150 milliseconds.

Another advantage of the proposed pyrometer is that it makes it possible to measure the color temperature of a detected body in several different wavelength ranges of its radiation at a time, this being possible due to its simple structure in adjustable manifolds and their easy adjustability. In the industrial process, it allows the selection of the optimal wavelength ranges for the object in question, guaranteeing the highest possible dimensional accuracy. When conducting studies, it allows the determination of the spectral properties of radiation emitting substances with high accuracy, optionally changing this at constant temperatures to different wavelength ranges, which in turn allows the study of the various physical and chemical processes that take place on the surface of these substances.

12 6391 1

Another advantage of the proposed color pyrometer is its high dynamic accuracy in measuring the color temperature of the radiating body, which results from its high response rate.

Furthermore, the proposed color pyrometer is easy to manufacture and the conversion of the pyrometer to different measuring ranges at the color temperature of the radiating body is carried out by simple adjustment of the matching parts in the measuring and attenuation channels.

The proposed color pyrometer allows the measurement of the color temperatures of a radiating body over a wide range from 300 to 3,000 ° C.

In addition, the proposed color pyrometer can be incorporated as a major component in devices that measure the color temperature of a radiating body by automatically correcting imperfect radiation properties from the detected body and using optional absorbents with known Absorption Laws. In this case, simultaneous application of measurement and correction is possible.

Although the present invention has been shown and described with reference to a preferred embodiment thereof, it is to be understood that one skilled in the art can, using the foregoing, make various changes in its form and detail without departing from the scope and principles of the present invention.

Claims (4)

1 3 6391 1 A color pyrometer comprising an optical device for directing the radiation emitted by the object to be measured into a narrow optical beam (2), a beam splitter (5) equipped with color filters and used to divide the optical beam (2), which becomes spatially separate optical devices rays (6, 7, 8) and to filter out different wavelengths of radiation from these separate optical rays (6, 7, 8), photovoltaic devices for detecting separated amounts of radiation with different wavelength ranges and providing electrical signals proportional to the intensity of the radiation an attenuation channel (14) of an electrical signal in which an electrical signal generated by one of the photovoltaic devices is attenuated to a predetermined value by a signal proportional to the radiation intensity in one of the wavelength ranges, this channel including an amplifier (26) amplifying the signal; yy reference pulse supply source (28) so as to compare this electrical signal with this reference pulse, in addition to which there is at least one measuring channel (12, 13) for measuring the electrical signal produced by the second photoelectric device proportional to the radiation intensity in the second wavelength range, also including an amplifier (18) for amplifying this electrical signal, characterized in that each of the channels (12, 13, 14) is provided with matching parts (15, 23) by which the electrical components of the photoelectric device connected to the input of said matching parts (15, 23) the parameters are adapted to the electrical characteristics of the divider part to be changed, the divider consisting of a resistor (16, 24) and an adjustable resistor type part (17, 25), the input of which is connected to the output of matching parts (15, 23); input, the delay part (29) being connected to the damping channel (14), while the measuring channel (1) 2, 13) is provided with an electronic switch (22), the output of the attenuation channel (14) amplifier (26) being connected to the input of the comparator (27), of which the output is 1 to 6891 1 connected to the inputs of adjustable resistor type parts (17, 25) in variable divisions via channels (12, 13, 14) and via a delay section (29) to the input of the electronic switch (22), the output of this electronic switch (22) being connected to the output of the matching part (15) of the measuring channel (13). Color pyrometer according to Claim 1, characterized in that the variable adjustable resistance-type parts (17, 25) in the measuring channel (12, 13) and the damping channel (14) are produced as a single integrated circuit, each adjustable resistance-type part (17, 25) comprising a transistor (34) from which the control electrode is connected to the output of the comparator (27), one of the output electrodes is connected to a resistor (16, 24) of the respective variable divider portion and the other output electrode is connected to a common point of the variable divider portions. 15 6391 1 1. A fidelity pyrometer equipped with an optical circuit, in which case a small optical fiber (2) is converted to an emitter with an optical field (M): a spatial filter (5) is used with a spurious filter to indicate the optical field of the optical circuit in the case of a separate optical filter (6,7,0) ooh to the on-board filter with a separate signal field (6,7,0) a separate photoelectric circuit for a separate signal from the signal field of the external signal source this is proportional to the intensity of the inertia; en electric signal signal reduction 1 (14) for a redundant signal in an electrical signal, the substrate of which is a photoelectric anode and is proportional to the power intensity of the signal, the color of the channel is shown a signal for said electrical signal and a comparator (27) with a reference pulse (20) for a signal equal to the electrical signal with a reference pulse; and a minimum of a single signal (12,13) for a signal with an electrical signal, with a substrate for the photoelectric anchorage and a proportion of the high intensity of the high-voltage signal; , att var och en av kanerna (12,13,14) försetts med ett anpassningsmedel (15,23) försetts av de elektrisk parametarna hos den photovoltaic anordningen, vil '* ·· ken kopplats till ineffekten till anpassningsmedlet (15,23) , after which the electric power supply has a variable power supply to the motor (16.24) and a controllable resistive element (17.25), the color does not affect the power supply to the power supply (15.23) The power supply to the power supply (15.23) 10.26); the feed means (29) being used in the reduction channel (14), the medium channel (12, 13) being provided with an electronic power supply (22); the effects on the mains (26) and the reduction channels (14) are combined with the effects of the comparator (27), or the effects with the controllers (17,25) of the variable control elements (12,13,14) of the channel (12,13,14). and through a set of devices (29) for ineffective and electronic devices (22),