High Precision Synchronous Detection Method for Multi-gas detection using a Single Laser

摘要

There are two main drawbacks seen in the use of the multi-gas detection method based on the tuneable diode laser absorption spectroscopy (TDLAS). The first is that multiple lasers have traditionally been employed in the detection system, which means not only the system cost, but also the system response time is increased. The second major issue is the existence of a number of kinds of cross interference, and thus the sensitivity and accuracy of the existing multi-component gas detection approach has been greatly restricted, and this has become a technical bottleneck for practical multi component gas detection. To address this, a synchronous detection technology for a high precision multi-component gas detection scheme using a single light source is reported. By measuring the spectral absorption feature of each individual gas at different concentrations, the relationship of each gas sample present to the spectral absorption value can be established and the concentrations of each individual gas can be calculated. This novel method has been shown to improve the precision achieved in the detection of the multi-component gas samples by20%, compared with the previous precision measured, with the induction in the interference effects on the measurements due to the different gases present, while at the same time reducing the detection cost and response time.