摘要
A photoacoustic （PA） spectrometer with H-type first longitudinal resonant cells for ammonia detection is developed. A new PA cell structure is designed to accelerate the drift velocity of the sample gas near the cell surface, so that the short response time at the flow rate of 100 seem （standard cubic centimeter per minute） is achieved. The response time of 5 min and detection limit of 0.86 ppbv is reached for ammonia concentration measurement with a Teflon polytetrafluoroethylene （PTFE） cell. Further improvement could be expected when using a brass cell with a high quality Teflon fluorinated ethylene propylene （FEP） coating.
A photoacoustic （PA） spectrometer with H-type first longitudinal resonant cells for ammonia detection is developed. A new PA cell structure is designed to accelerate the drift velocity of the sample gas near the cell surface, so that the short response time at the flow rate of 100 seem （standard cubic centimeter per minute） is achieved. The response time of 5 min and detection limit of 0.86 ppbv is reached for ammonia concentration measurement with a Teflon polytetrafluoroethylene （PTFE） cell. Further improvement could be expected when using a brass cell with a high quality Teflon fluorinated ethylene propylene （FEP） coating.
基金
This work was supported by the National Natural Science Foundation of China under Grant No.60677010.
