What things should be considered in using the 212R to measure H2 or other compounds in H2?
H2 in the gaseous state can be assumed to be one of two states, para H2 or ortho H2. Each has its own Thermal Conductivity Value. These differ by about 10% from one another. This must be taken into consideration when attempting to use the 212R on H2 streams. We would recommend one consult Wikipedia or other sources to learn more about these two states of H2 and how the thermal conductivity of the gas stream varies with the state. If for instance one is using pure H2 as a reference gas, and this gas is in the para state associated with cryogenic H2 recently vaporized, and this is then compared to cylinder H2 which may be in a different state, then considerable measurement errors can result. Plase contact Teledyne for further guidance or information on your specific application.
