Patent ID: 7740402
Filing Date: 2010-06-22
Classification: G01F,G01N

Abstract:
1. A detector for determining the presence of a fluid, the detector comprising: a probe having a thermistor, the probe being arranged to be exposed to the fluid and to allow thermal flow between the thermistor and the fluid; a first temperature sensor for measuring the temperature of the thermistor; a controller for supplying electrical power to the thermistor when it is below a predetermined temperature to heat it up and to turn off the supply of electrical power to the thermistor when it is at or above the predetermined temperature, and to determine the presence of the fluid exposed to the probe in accordance with the proportion of time that power is supplied to the thermistor to maintain it substantially at the predetermined temperature; wherein the controller is arranged to identify the fluid based on the proportion of time that power is supplied to the thermistor to maintain it substantially at the predetermined temperature; and wherein the controller has a memory including data correlating different types of fluids to different proportions of time that power is supplied to the thermistor to maintain it substantially at the predetermined temperature.