Methods for Response and Recovery Time Measurement of Hydrogen Sensors

Widespread use of hydrogen in the transport sector requires that associated safety issues be addressed and safety sensors will play an important role in doing so. These sensors must satisfy certain requirements in order to ensure that they can reliably and accurately alert to the presence of hydrogen - such performance standards are currently being laid in place. Our sensor testing facility has been constructed for the purpose of testing hydrogen sensors under various conditions. We have previously assessed the performance of a range of sensor technologies in terms of accuracy, measuring range, cross-sensitivity and dependence on ambient parameters. The work presented here aims at the development of a reliable method for evaluating sensor response t(90) and recovery times t(10). A number of methods have been tested, principally the "flow-through" and "diffusion-box" methods described in the draft ISO standard: ISO DIS 26142. The principal difficulty with these methods is in producing an instantaneous change in the test atmosphere. Our efforts have been directed at developing a method that both gives reproducible results and minimizes this changeover time. We report the optimum conditions found for the flow-through method, as well as improved variations of the diffusion-box method. These methods have then been used to test response and recovery times of a number of sensor technologies as a function of hydrogen concentration.

BLACK Grainne;  BRETT Lois;  MORETTO Pietro;  BOUSEK Jaroslav; 

2011-06-07

Forschungszentrum Julich

JRC58349

http://juwel.fz-juelich.de:8080/dspace/bitstream/2128/4200/1/SI2_4_Black.pdf,    https://publications.jrc.ec.europa.eu/repository/handle/JRC58349,