@article{ZHANG2018, 
author = {Qinduan ZHANG and Jun CHANG and Zongliang WANG and Fupeng WANG and Fengting JIANG and Mengyao WANG},
title = {SNR Improvement of QEPAS System by Preamplifier Circuit Optimization and Frequency Locked Technique},
year = {2018},
journal = {Photonic Sensors},
volume = {8},
number = {2},
pages = {127-133},
keywords = {QEPAS system, preamplifier circuit, frequency locked method, noise optimization},
url = {https://www.sciopen.com/article/10.1007/s13320-018-0468-y},
doi = {10.1007/s13320-018-0468-y},
abstract = {Preamplifier circuit noise is of great importance in quartz enhanced photoacoustic spectroscopy (QEPAS) system. In this paper, several noise sources are evaluated and discussed in detail. Based on the noise characteristics, the corresponding noise reduction method is proposed. In addition, a frequency locked technique is introduced to further optimize the QEPAS system noise and improve signal, which achieves a better performance than the conventional frequency scan method. As a result, the signal-to-noise ratio (SNR) could be increased 14 times by utilizing frequency locked technique and numerical averaging technique in the QEPAS system for water vapor detection.}
}