Seÿalar method and apparatus for the presence of a predetermined concentration of water in a bay oil.

摘要

A temperature sensitive resistor is immersed in a bath of quench oil and is supplied with electrical power sufficient to keep the resistor at a predetermined and substantially constant temperature above the vaporization point of water. When water is present in the oil, the water is vaporized by the resistor with the vaporization acting to cool the resistor and lower its resistance value. A signal which varies as a function of the drop in the resistance value of the resistor is produced and causes an increase in the power supplied to the resistor so as to keep the resistor at its predetermined temperature. In addition, transient pulses in the signal are detected and an alarm signal is produced when there is sufficient water present in the oil bath to cause the time-average value of the pulses to exceed a predetermined threshold. The resistor is protected from turbulence in the oil bath by a small chamber which contains a test sample of oil and which is periodically purged to bring a new test sample into the vicinity of the resistor and to allow the resistor to momentarily be exposed to air in order to clean slime and tar from the resistor.