A One ppm NDIR Methane Gas Sensor with Single Frequency Filter Denoising Algorithm

Sensors

Zipeng Zhu¹  Yuhui Xu² 

[1]College of Physics and Optoelectronics, Taiyuan University of Technology, Shanxi 030024, China

[2]RAE Systems (Shanghai) Inc., No. 990 East Hui Wang Road, JiaDing District, Shanghai 201815, China

[3] E-Mails:

关键词: methane;    NDIR;    FFT;    gas sensor;   

DOI  :  10.3390/s120912729

来源: mdpi

【 摘 要 】

A non-dispersive infrared (NDIR) methane gas sensor prototype has achieved a minimum detection limit of 1 parts per million by volume (ppm). The central idea of the design of the sensor is to decrease the detection limit by increasing the signal to noise ratio (SNR) of the system. In order to decrease the noise level, a single frequency filter algorithm based on fast Fourier transform (FFT) is adopted for signal processing. Through simulation and experiment, it is found that the full width at half maximum (FWHM) of the filter narrows with the extension of sampling period and the increase of lamp modulation frequency, and at some optimum sampling period and modulation frequency, the filtered signal maintains a noise to signal ratio of below 1/10,000. The sensor prototype provides the key techniques for a hand-held methane detector that has a low cost and a high resolution. Such a detector may facilitate the detection of leakage of city natural gas pipelines buried underground, the monitoring of landfill gas, the monitoring of air quality and so on.

【 授权许可】

CC BY   
© 2012 by the authors; licensee MDPI, Basel, Switzerland.