非分散红外二氧化碳检测仪研制

设计一种电调制、一体化的二氧化碳体积分数检测系统.该系统基于CO₂气体分子对红外光的特征吸收和Lambert-beer定律,采用双通道设计,由热释电传感器检测到的两路信号经过1 Hz低通放大电路处理后,输入示波器显示.为了避免光源波动对测量结果的影响,采用5 V稳压电路驱动红外光源,单片机对其进行1 Hz亮灭调制.对两路输出信号进行计算,可得CO₂体积分数.结果表明:检测仪量程为0%~80%,响应时间小于1.5 s.

Carbon Dioxide Detector Based on Non-Dispersed Infrared Principle

A compact non-dispersed infrared CO₂ measuring system using electrical modulated infrared source is designed. The system uses dual channel pyroelectric sensors to detect CO₂ molecular based on characteristic infrared absorption and Lambert-beer low. Two channels signals detected from pyroelectric sensor are filtered by 1 Hz low pass amplifier circuit. The measured result is displayed on an oscilloscope. In order to avoid measurement result is affected by light source fluctuation, the infrared light source is powered by 5 V voltage regulator circuit, and it is switched on and off with 1 Hz modulation frequency controlled by a single chip. The volume fractions of CO₂ is obtained according to the calculation of the tow output signal. Result shows that the detector has the measurement rang of 0%-80%, the response time less than 1.5 s.