Stray light jamming resistance photoelectric detecting system based on digital phase locking

Abstract

The invention relates to a photoelectric detecting system, in particular to a stray light jamming resistance photoelectric detecting system based on digital phase locking. The system comprises a light source, a TTL signal generator, an optical modulator, a sensor, a pre-amplifier and a lock-in amplifier, wherein the TTL signal generator or the optical modulator perform modulation on the light source, a modulated modulation light source and stray jamming light are converted into output measuring signals and jamming signals through the sensor, the measuring signals and the jamming signals are transmitted to the lock-in amplifier after being amplified by the pre-amplifier, and the lock-in amplifier is set to be only allowed to be passed by the measuring signals with the same frequency characteristics as the lock-in amplifier. According to the system, the measuring signal-to-noise ratio can be remarkably improved, the measuring lower limit can be effectively expanded on the condition that the light source power is not increased, and the system is particularly applicable to a pollutant monitor with the weak measuring signals, and is also applicable to stray light suppression of other optical measuring instruments.

Description

technical field [0001] The present invention relates to a photoelectric detection system, more specifically to a digital phase-locked anti-stray light interference photoelectric detection system, which belongs to the field of environmental monitoring devices. Background technique [0002] With the increasingly stringent environmental protection laws and regulations, pollutant monitoring instruments such as dust concentration measuring instruments and polluting gas analyzers are developing in the field of ultra-low emission technology, and the requirements for the measurement lower limit and sensitivity of monitoring instruments are increasing day by day. more and more applications. The treatment of the interference of natural light in the measurement environment, other ambient lighting and other miscellaneous and astigmatic light determines the measurement signal-to-noise ratio of the monitoring instrument, and then determines the performance and technical level of the measu...

AI Technical Summary

Problems solved by technology

[0003] At present, more and more optical detection technologies are used in the field of pollutant monitoring. Stray light interference often becomes an important problem affecting measurement accuracy and equipment stability. Especially in the ultra-low emission field, the existence of interference signals may make the equipment unusable.

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