【作者】：Nan Zhang,Bin Jiang,Shanshan Xue,Xiaolong Wang,Tianshuang Wang,Peng Sun,Geyu Lu
【题目】：General analysis method for the signal enhancement of microwave gas sensor though variation of energy loss
【关键词】：Dielectric loss tangent,Graphite powder,Permittivity variation,Microwave gas sensor,Ammonia
【版面信息】：Sensors and Actuators B: Chemical Volume 367, 15 September 2022, 132117
摘要:
Microwave gas sensor (MGS) becomes a highlight recently because it can work at the room temperature (20 ℃)
and has potential wireless application. However, there are still some problems such as low sensitivity and
linearity. In this short communication, a novel analysis method based on variation of energy loss was proposed as
sensor response for the first time. The as-prepared device is successfully used for NH3detection based on
commercial graphite powder which can achieve a low detection limit (1 ppm, 20 ℃), excellent selectivity and
humidity-resistance (20–95% RH). Moreover, the sensor shows good linearity for low concentration range of NH3
from 1 to 5 ppm (R2 = 0.999) or high concentration range from 10 to 200 ppm (R2 = 0.99) through analyzing
energy loss calculated by both reflection and transmission, which is more linear compared with that only using
reflection or transmission. Therefore, this study provides a simple and universal method for response signal
analysis, which can amplify the weak sensing signal then realize high-performance MGS.
