Measurement of Undissolved Water Content in Jet Engine Fuels by a Dielcometric Transducer

Abstract

A method and a device are developed to determine the undissolved water content in jet engine fuels under dynamic conditions. The device consists of a sampler, a thermostatically controlled chamber, an undissolved water separation unit, and a unit for measuring the dielectric constant of dewatered and water-containing fuel. Dewatered fuel acts as internal ethanol, and the dielectric constant of ethanol and dewatered fuel is measured at the same temperature.A source of danger in aviation is the presence of water in the fuel. In winter conditions on the ground and during long flights jet fuels can be cooled to -40 --60 °C. Under these conditions, formation of ice crystals in the fuel is probable, which can clog the supply system and cause an accident. Therefore, aircraft refueling facilities have special requirements -the content of free water in the fuel should not exceed 0.0015 wt. % [13].In most cases, the dielcometric method GOST 14203-69 "Oil and Oil Products. Dielcometric Method for Determining the Moisture Content." is used for the determination of free (undissolved) water. The essence of the method is in applying moisture meters, consisting of capacitive sensors and measurement units, which convert the change in capacitance of the sensor caused by varying moisture in the oil into an output signal.