Due to the cold temperatures below sea, as well as the cooling effect of reducing the pressure of a gas, it is vitally important to avoid excess moisture in the UHP air. If ice formed it could block or damage the equipment and completely disable the submarine.
One of Michell’s long-standing customers, S.A. Marine Pty. Ltd from Australia specialise in evaluating and testing UHP air systems. Due to the high pressures involved, it’s vitally important that the air is pure and free from contaminants such as compressor oil particulates or water.
S.A. Marine uses a desiccant dryer to remove vapour from the air and use an on-line hygrometer from Michell to measure the water dew point at delivery, as part of their portable test set. The Michell ceramic impedance sensor is able to measure the dew-point temperature at line pressure which gives S.A. Marine complete confidence in their measurements.
They also provide an inspection service for breathing air cylinder-filling apparatus for both naval and commercial customers. In this case, too much moisture would lead to the potential bacteria to grow and pose health problems for the users. Back at their company facilities, S.A. Marine use a Michell chilled mirror hygrometer as a high-precision calibration reference on a test rig.
Greg Fahill, the managing director of S.A. Marine said: ‘Michell offer the only hygrometers we have found to be reliable at UHP conditions.’
• Michell Instruments are marketed in Ireland through Instrument Technology.