The Crouse-Hinds series MTL K1650 analyser was designed specifically for use in power stations. Modern turbogenerators produce a great amount of heat and the most efficient way of removing this heat is by enveloping the parts in hydrogen because hydrogen has seven times the cooling capacity of air. It is possible, however, for air to leak into the system, so it is essential to monitor the hydrogen purity for both efficiency and safety, as an air mixture will produce a potentially explosive atmosphere.
When maintenance needs to be performed, the atmosphere surrounding the turbogenerator must be replaced with air. This cannot be a direct replacement because of the explosive mixture that would be produced in the process. Instead, an inert gas, usually carbon dioxide, is used to purge the hydrogen, then air is introduced to purge the carbon dioxide. The same procedure must be followed in reverse when replacing the hydrogen atmosphere.
The K1650 analyser has three ranges to monitor hydrogen purity and the shut down/start up purge stages of generators.