In Photoacoustic detection the light absorbed by the molecules by a pulsed light source is transformed in a pressure wave that can measured by a standard microphone. The intensity of the sound is proportional to the concentration of the chemical in the gas mixture.
In the configuration proposed, called Differential Helmholtz Resonator, two acoustic resonators are coupled by capillaries in a configuration immune to external noises.
For deployment in applications requiring high performances and low costs, such as greenhouse gases survey or indoor air monitoring.
- Architecture: Differential Helmholtz Resonator
- Use of commercial MEMS microphone;
- Compatible with any light source
- Sub-ppm range detection capabilities
- Typical integration time: 1 s to 10 s
- Static or low gas flow
- Tested on CO2, CH4, CO
- High temperature operation
- New high performances microphones