The sensors feature two thermal conductivity dies in a surface-mount package for increased stability. Hydrogen sensors from Posifa Technologies detect hydrogen concentrations in the air by measuring the change in thermal conductivity of the gas mixture.
The PGS1000 series is based on Posifa's second-generation thermal conductivity die. The devices feature one die sealed in dry air and acting as a reference, while the other is exposed to the gas mixture. This design enables an excellent signal-to-noise ratio due to common-mode noise rejection and a maximization of the signal amplification. For safe operation, the sensor is excited with a pulsed waveform (400ms on and 1s off) to minimize the heater temperature.
The sensors released today are suitable for hydrogen leak detection and monitoring in industrial processes, medical facilities, and automotive fuel cells. For these applications, the devices combine fast response times of <1.4s with the broadest available ranges — up to 100 percent volume — and typical long-term stability of 0.1 percent full scale/year.
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