RU2445587C1 - Method of calibrating pulsed pyrometer - Google Patents

Abstract

FIELD: physics.

SUBSTANCE: after focusing the optical system, the radiation spectrum of the reference source which is placed at the focal point is recorded using a spectrometer. The spectrometer is calibrated in pulsed mode using light-emitting diodes with wavelength which corresponds to the wavelength of each channel of the pyrometer. The procedure is carried out for each channel separately. Measurement channels of the pyrometer are calibrated by recording the amplitude of pulses from photodetectors of the pyrometer in volts for each light-emitting diode separately. By transmitting a single pulse from the pulse generator to the light-emitting diode in manual trigger mode, the total radiation power of the light-emitting diode per pulse is determined. That power is transmitted to the photodetector of the pyrometer and the division value for each channel of the pyrometer in watts is determined.

EFFECT: calibration of pulsed pyrometer channels based on radiance.

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Description

The invention relates to measuring technique, namely to optical non-contact methods for measuring the rapidly changing true temperatures of various objects, and can be used in pyrometry, spectrometry, laser and light engineering in the study of fast processes.

A known method of calibrating a pyrometer, which consists in the fact that the known incandescent lamp - a constant light source shines in the photodetector (photodiode, etc.). A disk chopper is located between the lamp and the receiver, which modulates the continuous radiation of the lamp to avoid saturation of the photodetector. The current pulses on the photodiode are recorded by an oscilloscope. These values correspond to the brightness of a certified lamp. Further, the temperature is calculated by the ratio of brightnesses at different wavelengths. "Boslough, Mark B .; Ahrens, Thomas J. “A sensitive time-resolved radiation pyrometer for shock temperature measurements above 1500 K,” Review of Scientific Instruments, ”vol. 60, Dec.1989, p. 3711-3716.

The disadvantages of this method is the inability to obtain a single pulse of reference radiation for calibration due to the periodically rotating disk chopper. Another disadvantage is the long pulse duration, and as a result, the inability to calibrate high-speed pyrometers due to the use of a mechanically rotating disk.

A known method of calibrating a pyrometer, which consists in the fact that the known incandescent lamp - a constant light source shines in the photodetector (photodiode, etc.). The lamp is calibrated and current flows from the lamp on the photodiode, which is recorded by the oscilloscope. These voltage values correspond to the brightness of a certified lamp. Further, the temperature is calculated by the ratio of brightnesses at different wavelengths. “Pavel Ni“ Temperature measurement of high-energy-density matter generated by intense heavy ion beam ”, Doktors der Naturwissenschaften”, Darmstadt 2006, pp. 36-39.

The disadvantage of this method is the inability to calibrate the channels of the pulsed pyrometer by energy brightness.

The technical result of the invention is the calibration of the channels of the pulsed pyrometer by energy brightness.

The technical result is achieved by using a reference source of static light radiation and a pyrometer photodetector to calibrate the channels by energy brightness, after focusing the optical system, the emission spectrum of a reference source installed at the focusing point is recorded using LEDs with a wavelength corresponding to the wavelength of each channel of the pyrometer , calibrate the spectrometer in a pulsed mode, applying short pulses from the pulse generator to the LED installed at the focus point pulses, the total amplitude of the recorded spectrum of which is equal to the amplitude of the radiation from the tungsten lamp, the procedure is carried out for each channel separately, the measuring channels of the pyrometer are calibrated, recording the amplitude of the pulses from the pyrometer photodetectors in volts for each LED installed at the focusing point, separately, applying from the generator pulses per LED in the manual start mode, a single pulse, and determine the total radiation power of the LED for each channel of the pyrometer, per I’m on one pulse, and this power is supplied to the photodetector of the pyrometer, and then the division price for each channel of the pyrometer in watts is determined, after measurements are taken, the temperature is determined by the Planck relation.

The invention is illustrated in figures 1-4.

Figure 1 presents a diagram of the calibration of the spectrometer in static mode, where: 1 - a reference source of static light, for example, a tungsten lamp SIRSH 8.5 200-1, as a working standard; 2 - experimental unit (for example, a light radiation detector); 3 - working fiber; 4 - spectrometer on a CCD line.

Figure 2 presents a diagram of the calibration of the spectrometer in a pulsed mode, where: 2 - experimental unit (for example, a light radiation detector); 3 - working fiber; 4 - spectrometer on a CCD line; 5 - LED block; 6 - generator of rectangular pulses.

Figure 3 presents a diagram of the calibration of the pyrometer in a pulsed mode, where: 2 - experimental unit (for example, a light radiation detector); 3 - working fiber; 5 - LED block; 6 - a generator of rectangular pulses; 7 - photodetector of the pyrometer.

Figure 4 schematically shows a detector of light radiation, where: 3 - working fiber; 8 - the housing of the experimental unit; 9 - optical lens; 10 - a glass for indicator fluid or indicator glass; 11 - test sample.

The calibration method is implemented as follows. Calibration of the pyrometer is carried out each time immediately before conducting explosive experiments with specific experimental units and working optical fibers involved in the experiment.

In the static mode, the emission spectrum N _ETALON (λ) is recorded, the reference source of static light 1, for example, on the basis of an incandescent lamp with a tungsten tape, a tungsten lamp SIRSh 8.5 200-1, spectrometer 4 (Fig. 1).

Metrological characteristics are transferred from a static reference light source based on an incandescent lamp with a tungsten tape to a pulsed light source based on a LED and a rectangular pulse generator using a charge-coupled spectrometer (CCD matrix), which uses the property of independence of charge storage CCD depending on the type of impact (pulsed or static), and the photodetector of the pyrometer is calibrated using the secondary pulsed energy standard brightness on the basis of an LED and a rectangular pulse generator.

Using various LEDs 5 with a wavelength corresponding to the wavelength of the channel of the pyrometer, calibrate the spectrometer 4 in a pulsed mode.

To do this, from the pulse generator 6, short pulses are supplied to the LED 5 in such a quantity that the total amplitude of the recorded spectrum N _LED (λ) is equal to the amplitude of the reference source of static radiation 1. The procedure is repeated for each channel separately (figure 2).

Calibrate the measuring channels of the pyrometer by registering the amplitude of the pulses from the photodetectors of the pyrometer 7 with oscilloscopes in volts for each LED 5 separately, applying a single pulse from the pulse generator 6 to LED 5 in the manual start mode (Fig. 3).

The total radiation power for each of the six channels per one pulse is determined. It is this light emission power from the photodiode 5 that is supplied to the pyrometer photodetector 7.

The total power is determined by the formula (1).

where: S _SD - the sum of the number of samples in the spectrometer in the wavelength range from λ _i to λ _i + Δλ from the LED,

;

;

S _ETALON - the number of samples in the spectrometer in the wavelength range from λ _i to λ _i + Δλ from the reference source of static radiation;

P _REFERENCE (λ _i ) - value from the certificate of verification for a reference source of static radiation at a wavelength λ;

P _LED (λ _i ) is the radiation power of the LED at a wavelength λ.

λ _i + Δλ is the channel width of the pyrometer.

Knowing the amplitude in volts and using the linearity of the oscilloscope scale, the channel division price is determined for each oscilloscope (each channel of the pyrometer separately) in watts.

When conducting experiments, a glass 10 for the indicator liquid or indicator glass and the test sample 11 are installed at the focus point of the case of the experimental unit 8. The processes of changing the glow intensity of the energy brightness are observed. The temperature is determined using the known Planck relation:

where: λ is the wavelength, m; T is the temperature, K; h is the constant bar, J · s; k is the Boltzmann constant, J / K; C is the speed of light in vacuum, m / s.

After carrying out the steps described above, it is believed that the pyrometer (with a specific experimental unit and a specific fiber) is calibrated and ready for an explosive experiment. Using the calibration files saved earlier, the amplitude scale, measured earlier in volts, after the calibration has a dimension - W (watts).

Claims (1)

A method of calibrating a pulsed pyrometer, which consists in the fact that to calibrate the channels according to the energy brightness, a reference source of static light radiation and a photodetector of the pyrometer are used, characterized in that after focusing the optical system, the radiation spectrum of the reference source installed at the focus point is recorded using LEDs with a length waves corresponding to the wavelength of each channel of the pyrometer, calibrate the spectrometer in a pulsed mode, applying from the pulse generator to the LED, installed at the focus point, short pulses, the total amplitude of the recorded spectrum of which is equal to the amplitude of the radiation from the tungsten lamp, the procedure is carried out for each channel separately, the measuring channels of the pyrometer are calibrated, recording the amplitude of the pulses from the pyrometer photodetectors in volts for each LED installed at the focus point, separately, applying a single pulse from the pulse generator to the LED in the manual start mode, and determine the total radiation power of the LED d For each channel of the pyrometer, per pulse, this power is supplied to the photodetector of the pyrometer, and then the division price for each channel of the pyrometer is determined in watts, after the measurements, the temperature is determined by the Planck relation.

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