Thermal conductivity multiple gas sensor: hydrogen (H2)
425 Series Nova Analytical Systems

The Nova 425 Thermal conductivity (TC) Analyzer has many applications in industry where the measurement of one gas in a two gas or some multi-gas mixtures is required. The Nova TC cell is temperature controlled and its high stability enables it to be used even in high purity measurements. Since the TC cell does not consume the sample, have any moving parts, hot wires, or sealed chemicals, it will last for many years.
In operation, the TC cell detects the rate at which the sample gas conducts heat away from a Resistance Temperature Device (RTD) with reference to a similar RTD surrounded by air (or other reference gas). A sample gas containing the gas to be measured will cause the temperature, and its resistance, to change with respect to the reference RTD. This will cause an output from the Wheatstone bridge measuring circuit which is calibrated and displayed on a digital meter.