Skinner, A.Lambert, M.2010-04-062010-04-062009IEEE Sensors Journal, 2009; 9(9):1049-10571530-437X1558-1748http://hdl.handle.net/2440/57328© Copyright 2009 IEEEWarm-thermistor sensors are useful for making measurements of flow and the thermal properties of materials. This paper describes a log-antilog analog control circuit capable of monitoring a thermistor's internal temperature in both ambient temperature sensing mode and self-heating mode, while maintaining infinite precision, wide dynamic range and fast sensor response. A single self-referencing thermistor is used to avoid the problems associated with having to match a thermistor pair in order to obtain an over-temperature signal. Instead, thermistor power levels are switched over a range of 1:1000, allowing measurement of both ambient temperature and heated thermistor temperature during the rise and fall of the heat pulse by a single thermistor at the center of the heat field. This provides a sensitive measurement of the thermal diffusivity and advective properties of the surrounding medium. In this paper, such a sensor is used to investigate the thermal properties of a grapevine cane under conditions of irrigation stress.enLog-antilogplant water statusthermal diffusivity sensorwarm thermistor sensors.Journal article002009166510.1109/JSEN.2009.20240570002687571000012-s2.0-7814924011538175Lambert, M. [0000-0001-8272-6697]