Digital automatic frequency locking photoelectric equivalent balance system of electrical calibration heat radiometer

Abstract

The invention relates to a digital automatic frequency locking photoelectric equivalent balance system of an electrical calibration heat radiometer. Through a high-precision optical chopper, optical radiation is irradiated to a pyroelectric detector. The detector outputs a weak electrical signal. After going through a weak signal detection circuit, an automatic tracking band pass filter, an automatic tracking phase sensitive detection circuit, a compensation integrating circuit, and an electric heating signal modulation circuit in order, the signal is modulated into two paths of electric heating signals with symmetrical waveform and alternate polarity. The two paths of electric heating signals are outputted to two electric heating electrodes of the detector respectively. The system can besuitable for reference signals with different frequency and lock and track reference signal frequency, and automatic coupling of phases of an optical radiation heating signal and an electrical power heating signal can be realized. Adaptation capability of an electrical calibration radiometer in different occasions is increased, and a usage scope is enlarged. Simultaneously, according to an automatic phase coupling function, a series precision influence problems brought by a hand-operated adjusting mode can be substantially reduced.

Description

technical field [0001] The invention relates to a measuring instrument, in particular to a digital automatic frequency-locking photoelectric equivalent balance system for an electric calibration thermal radiation meter. Background technique [0002] The electric calibration pyroelectric radiometer is a high-precision electrical substitution absolute radiometer for measuring the optical radiation power. It uses the optical radiation power signal and the electric power signal to heat the surface of the detector device separately, so that the detector reaches thermal equilibrium and realizes photoelectricity, etc. The basic principle of efficiency, the value of optical radiation power is obtained by accurately measuring the power value of electric heating. This method can trace the measurement standard of optical radiation power to the standard of electrical power measurement, so high precision can be obtained. [0003] The photoelectric heating balance system is the core unit...

AI Technical Summary

Problems solved by technology

[0005] The present invention is aimed at the problem that the defects of the current electric calibration pyroelectric radiometer limit the use range, and proposes a digital automatic frequency-locking photoelectric equivalent balance system for the electrical calibration pyroelectric radiometer, which can adapt to reference signals of different frequencies , lock and track the frequency of the reference signal, and can automatically match the phase of the optical radiation heating signal and the electrical power heating signal

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