Research on Detection System of Weak Gas Signal Based on DSP

In order to be better detection of weak gas signal, the detection technology was improved based on the lock phase amplified detection principle of the weak signal. On the basis of the combination of analog filter and digital filter, the system was developed to detect the weak gas signal. The output signal of infrared gas sensor was amplified and filtered by analog circuits, then, was sampled by high performance microcontroller (DSP) and filtered by digital low-pass filter algorithm. The results showed that the detection technology could achieve the full filtering. It had an obvious advantage not only in precision but also in velocity and could achieve the real-time measurement of gas concentration. It would be used abroad for detection of methane in some industrial fields.