Hydrogen Tech World August 2023 | Page 32

[ instrumentation ]
Production under strict laboratory conditions
Corrosive gases are present in certain processes , which must also be taken into account . Additionally , extra sample preparation due to , for example , high operating pressures , humidity or process temperatures , may also be needed .
The importance of measurement precision and speed in the hydrogen process chain mentioned above cannot be overstated . The same is true for a compact design of the sensor systems for flexible plant construction and , of course , their sheer number . The demand for these sensors is enormous if one really wants to achieve a move away from fossil fuels with the help of hydrogen . Quality and quantity are both essential , so what is the ideal way to meet both with the help of new or optimized measurement technology ? Innovative developers have found the answer .
Precise , fast and reliable
Due to the wide range of applications for hydrogen technology , sensor systems with the largest possible dynamic range are required . Very importantly , the sensors should be able to detect both relatively high hydrogen concentrations
in the percentage range and extremely low concentrations in the ppm range in gas mixtures . Sensor solutions based on the thermal conductivity measurement principle seem wellsuited , since hydrogen has a significantly higher thermal conductivity compared to other gases ( only helium is comparable ). Innovative solutions based on the proven thermal conductivity detector ( TCD ) sensor technology make use of the thermal conductivity in an optimized form and can determine the hydrogen concentration in gas mixtures extremely precisely . High precision of the thermal conductivity of gas measuring instruments is only possible if the temperature is under control . And this is only possible if the sensors and the evaluation electronics interact extremely finely and quickly .
Answers to these challenges have been found , for example , by Archigas GmbH ( Rüsselsheim , Germany ) with their new developments . In cooperation with the RheinMain University of Applied Sciences ( HSRM ), they realised a novel design of MEMS ( see below ), whereby the thermal changes can be detected exceptionally well due
32 Hydrogen Tech World | Issue 11 | August 2023