Patent ID: 7874724
Filing Date: 2011-01-25
Classification: F04B,G01F,G01K

Abstract:
1. A method for sensing a fluid in a compressor, wherein the fluid can exist in a plurality of states including at least one of a liquid state, a gaseous state, and a gas/liquid mixture, the method comprising: positioning a thermistor in heat transfer relationship with the fluid, wherein the thermistor has a thermistor temperature that varies; providing a feedback signal that varies with the thermistor temperature; obtaining a ripple signal by a conventional method step wherein the ripple signal is indicative of voltage fluctuation; adding the ripple signal to the feedback signal to create a dithered input; calculating a dither-based temperature value based on the dithered input; and based on the dither-based temperature value, determining at least one of the following: a) a state of the fluid, and b) a temperature of the fluid.