通过对国内外现有恶臭测量方法的研究并结合现有光电检测技术,提出一种基于光吸收的恶臭信号采集系统.该系统基于光电比色法,采用双光路即每个采集电路模块设两个光路:一路参考光,一路信号光,两路信号采集时都使用了双边带调幅技术,相敏解调后的两路信号进入差分放大器做差,并且将差分信号用宽量程可编程增益放大器放大至理想AD值.该系统适合于采集宽范围浓度的恶臭信号,尤其适合于测量微弱的恶臭信号.该方案不仅能够抵抗干扰,降低噪声,还可提高采集的灵敏度,增大了量程,具有较好的应用前景.%By studying the available stench detecting methods at home and abroad,a stench signal acquisition system based on light absorption is proposed in combination with the existing photoelectric detection technology. The system is based on the photoelectric colorimetry. The double optical paths are adopted in the system for each acquisition circuit module. One path is the reference light and another is the signal light. The double-sideband amplitude modulation technology is used for signal acqui-sition of the two paths. The dual-path signals after phase sensitive demodulation are transmitted into the differential amplifier for subtracting. The differential signal is amplified with the wide-range programmable gain amplifier until a satisfied A/D value is ob-tained. The system is suitable for acquisition of the stench signal in wide range,especially suitable for detection of the weak stench signal. The design scheme can resist the interference,lower the noise,improve the acquisition sensitivity and detecting range,and has a good application prospect.
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