Digital signal processing and controlling system of nondispersive infrared gas analyzer

Abstract

The invention relates to the field of component detection, in particular to a digital signal processing and controlling system of a non-dispersive infrared gas analyzer. A digital signal processor (DSP) is used as a core of the digital signal processing and controlling system. The digital signal processing and controlling system comprises a DSP chip, an infrared signal conditioning circuit, a 24-bit analog-to-digital converter (ADC) circuit, a temperature acquiring circuit, a gas pressure acquiring circuit, a 16-bit ADC circuit, an external expansion static random access memory (SRAM) circuit, a ferroelectric memory circuit, a real-time clock circuit, a reset circuit with a watchdog and a power monitor, a thermal resistance driving circuit, a key circuit, a digital output circuit, an RS-232 / 485 interface, a liquid crystal display circuit, a 4-20mA / 0-20mA output circuit and software. The amplitude of signals is solved by a spectral analysis method based on fast Fourier transform (FFT), the center of gravity is corrected, the amplitude of the signals is measured accurately, and signal processing accuracy is guaranteed; a mathematical model which meets requirements on engineering application is set up, and the relation between input and output is non-linearly corrected; and temperatures are controlled by using a proportion-integration (PI) control algorithm based on pulse-width modulation (PWM).

Description

technical field [0001] The invention relates to the field of component detection, and is a non-dispersive infrared gas analyzer, in particular a digital signal processing and control system of the non-dispersive infrared gas analyzer with DSP as the core. Background technique [0002] The infrared gas analyzer is an instrument designed according to the principle of selective absorption of the infrared spectrum by the gas to be measured, and is used to measure the gas volume concentration. It can continuously and automatically measure, indicate and record CO, CO 2 、CH 4 , SO 2 , NO and other gas volume concentrations to be measured. Due to the advantages of high sensitivity and good stability, infrared gas analyzers are widely used in gas analysis of electric power, petroleum, chemical industry, building materials, light industry and other furnaces, kilns or flues. , Medical and health and other scientific research work indispensable detection tools. [0003] Infrared li...

AI Technical Summary

Problems solved by technology

For example, the improved product EL3020 infrared gas analyzer launched by ABB claims to apply the method of digital signal processing to the infrared gas analyzer, but no technical details are disclosed

Images