An online methane sensor was employed to monitor methane level in the sewage at the end of a rising main for a period of 3 weeks during both winter and summer periods. Based on the sewer information and the pump station operation data, a model was setup for the sewer system. The SeweX model, capable of predicting methane generation in a sewer, was employed for this purpose. The model was calibr...

Detection of methyl mercaptan (CH₃SH) is essential for environmental atmosphere assessment and exhaled-breath analysis. This paper presents a sensitive CH₃SH sensor based on wavelength modulation spectroscopy (WMS) with a mid-infrared distributed feedback interband cascade laser (DFB-ICL). Multicomponent spectral fitting was used not only to enhance the sensitivity of the sensor but also to det...

A miniature methane sensor composed of a long ultra-low loss waveguide and a micro-ring resonator filter is proposed with high sensitivity and good selectivity. This sensor takes advantage of the evanescent field to implement methane concentration detection at a near infrared band (1650 nm). In the sensor, two waveguides, a strip waveguide and a slot waveguide, are specially designed and discus...

Chemiresistive sensors are promising devices for sensing hydrogen gas in a broad range of applications including fuel cells, storage systems, petroleum refinement, and diagnosis oil-insulated transformers. Herein, electrospun ZnO–SnO2 belts (BLs) were synthesized applied as resistive-type layers sensing. The BLs containing 20 mol% Zn relative to Sn showed response (Ra/Rg, Ra: resistance air, Rg...

The parameters of gas-liquid two-phase flow bubbles in field coalbed methane (CBM) wells are of great significance for analyzing coalbed methane output, judging faults in CBM wells, and developing gas drainage and extraction processes, which stimulates an urgent need for detecting bubble parameters for CBM wells in the field. However, existing bubble detectors cannot meet the requirements of th...

zno and zno: mn nanocrystals were synthesized via reverse micelle method. the structural properties of nanocrystals were investigated by xrd. the xrd results indicated that the synthesized nanocrystals had a pure wurtzite (hexagonal phase) structure. resistive gas sensors were fabricated by providing ohmic contacts on the tablet obtained from compressed nanocrystals powder and the installation ...

This study was focused on how to improve the gas sensing properties of resistive gas sensors based on zinc oxide to dimethyl sulfide (DMS). The aim of this research was to investigate possible ways of improvement detection of dimethyl sulfide, such as volume doping with synthesized gold nanoparticles or applying sepiolite passive filter. The addition of noble metal into the gas sensing layer is...

A novel smart resistive-capacitive angular position sensor is presented. The main advantages of this low-cost system are its simplicity, high stability and high reliability. A very hear oscillator is used in the processing circuit to convert the position quantity to a period-modulated signal which can directly be read out by a microcontroller. The system does not need an A/D converter. The nonl...