Detection of trace carbon monoxide based on cantilever enhanced photoacoustic spectroscopy at 2.33 μm

•The cantilever enhanced photoacoustic spectroscopy detection system is built up to carries out the photoacoustic spectroscopy detection of CO, which reaches the lower detection limit with 5.1 ppm when SF6 as the background gas.•The researches studies the influence of the background gas and temperature on the photoacoustic on the detection quantificationally, which reveals its influence mechanism. The composition gases internal SF6 insulation equipment is closely related to the insulation state of the equipment. According to relevant regulations, CO is an important component, and its concentration can be used as the basis for judging the internal insulation state of SF6 equipment. Gas detection based on photoacoustic spectroscopy is an effective means of online monitoring. The study adopts the 2.33 μm distributed feedback semiconductor laser as light source and the cantilever as acoustic sensor to develop the photoacoustic spectroscopy detection system, performs the photoacoustic spectroscopy detection of CO, and studies the influence mechanism of the background gas and temperature on the excited photoacoustic signals. The results show that the signal has high stability and a good linear relationship with the gas concentration. The lowest detection limit of CO in SF6 is 5.1 ppm, and the background gas and temperature mainly affect the excited signals by the difference of the cell constant.