Hydrogen Measurements on Combustion Engines



Hydrogen is the most important compound in catalyst reduction reactions, generated either during enriched operation in normal aspirated engines or during post injection in common rail engines. At sufficiently high cylinder temperatures dissociation of fuel molecules into radicals initiates a fast recombination of protons into H2. This process can deliver an output between 0.6% and 2 Vol% of H2. Catalytic NOx reduction in diesel engines is based on the reaction of hydrogen with the NOx. In order to develop and improve such technologies precise and time-resolved measurements of hydrogen are required.


The V&F HSense is capable of monitoring the engine out hydrogen levels in real time. Core of this fast and reliable instrument is a sector field mass spectrometer that allows for hydrogen measurements at concentration levels from below 1 ppm up to 100 %. An integrated cooling device avoids any cross-interferences that could otherwise be caused by H2O in the engine out gas. Automatic pressure regulation from 0.5 to 3 bar, accessible and user friendly V&F software paired with the robustness of system as a whole make the HSense a highly valuable tool for the automotive engineer. As with all other V&F instruments a variety of interface options such as AK protocol ensure easy implementation into the test bench environment.


The HSense mass spectrometer is currently the only instrument on the market that can measure engine out hydrogen from 0 – 100 % in real time. Unlike other technologies based on electrochemical and thermal conductivity principles the HSense is free of cross sensitivity to other components present in the engine out gas. The sector field analyzer is selectively adjusted to the analysis of hydrogen. Setup of the instrument is completed within 60 minutes.


  • Magnetic sector field technology
  • Real time H2 measurements
  • AK interface available

Reference customers (excerpt)


Applicable instruments