Hydrogen Sensors

PGS1000 oxygen sensor

The PGS1000 Series of hydrogen sensors detects hydrogen concentration in air by measuring the change in thermal conductivity of the gas mixture.

Hydrogen and air have very different thermal conductivity. Variation in hydrogen concentration results in significant changes in the thermal conductivity of the gas mixture.

The PGS1000 Series uses 2 thermal conductivity dies in a differential configuration: one sealed in dry air and acting as a reference; the other exposed to the gas mixture. Such a design achieves an excellent signal-to-noise ratio due to common-mode noise rejection and maximization of signal amplification. In addition, the sensor is excited with a pulsed waveform (400 ms on and 1000 ms off), resulting in a heater temperature that is almost the same as the ambient. This feature lend intrinsic safety to the sensor.

Posifa's hydrogen sensors perform optimally in applications where interfering gases are absent, or their cross-sensitivity is within the acceptable margin of error required by the application. These low-cost devices offer fast response times and long-term stability.


  • Broadest available ranges, up to 100% volume
  • Fast response time of less than 1.4 seconds
  • Temperature-compensated
  • Pulsed excitation minimizes heater temperature for safe operation
  • Operating temperature from -25°C to 85°C
  • Shock: 100g peak (5 drops, 3 axes)
  • Repeatability 0.05% FS


  • Hydrogen leak detection
  • Process monitoring
  • Fuel cells