Different carbon monoxide sensors

Different carbon monoxide sensors

   Semiconductor carbon monoxide sensor is obtained by a sol-gel method to obtain a SnO2-based material, and a metal catalyst is doped in the base material to determine a gas. At present, there are studies on the doping of Pt, Pd, Au, etc. in SnO2-based materials, and it is found that when the sensor is operated at 220 °C, when the SnO2 is doped with 2% Pt, the sensor has the greatest sensitivity to CO. Due to the cross-sensing of the Gas Sensor, the CO sensor is sensitive to many gases such as H2, CO2, H2O, etc., but the above method makes the sensitivity to other gases much lower.

   Electrochemical principle CO sensor sensitive electrode, such as common metal material electrochemical electrode, has transition metal elements such as Pt, Au, W, Ag, Ir, Cu, etc. These elements have spare d, f electron orbitals and redundant d, f electrons. It can provide electron vacancies or electrons in the process of redox, and can also form complexes with strong catalytic ability. A new type of CO electrochemical Gas Sensor was developed, which self-assembled multi-walled carbon nanotubes onto a platinum microelectrode to prepare a multi-walled carbon nanotube powder microelectrode, which was used as a working electrode and Ag/AgCl as a reference. The electrode, the Pt wire is a comparative electrode, and the porous polytetrafluoroethylene film is used as a gas permeable membrane to make a sensor, which has a remarkable electrochemical catalytic effect on CO, and has a short response time and good repeatability.

   Based on the near-infrared absorption mechanism of CO gas, a spectral absorption type optical fiber CO Gas Sensor was studied. The detection sensitivity of the instrument can reach 0.2×10-6. Another type of optical sensor is a sol-gel hydrochloric acid catalyzed method and ultrasonic SiO2 film, the film is immersed in a mixed solution of palladium chloride and copper chloride, uniformly pulled, dried to obtain a sensitive film, using palladium salt and The CO reacts to form a palladium element, causing a change in absorbance.