Photoacoustic Sensors for the Detection of Sulfuryl Difluoride and Water Vapor

This dissertation discusses the detection of two gases, sulfuryl difluoride (SO₂F₂) and water vapor (H₂O). Both gases are detected using photoacoustic sensors based on the two-chamber approach. Simulations regarding the response of photoacoustic detectors to the target gases (SO₂F₂ and H₂O) and to interfering gases are performed and presented in the first part of the dissertation. The photoacoustic detectors were developed, filled with gas and characterized. In the next part of the dissertation, the development of photoacoustic SO₂F₂ sensors for two concentration ranges 0-1 vol.-% SO₂F₂ and 0-100 ppm SO₂F₂ as well as a photoacoustic H₂O sensor for the concentration range 0-6000 ppm H₂O is presented. In the case of measuring SO₂F₂, a thermal IR emitter was used as an IR source, while in the case of H₂O, a thermal IR emitter and an MIR LED were used. The response of the sensors to the target gases and to interfering gases was experimentally investigated and the detection limit of each system was determined.