Miniaturized thin film temperature sensor for wide range of measurements

This work is dedicated to the development of a sensor prototype for the measurement of high temperatures of solids, liquids and gases, in a range of 0 - 800degC with an accuracy of 0.1degC. Operative range may be extended also to cryogenic temperatures. Sensor may be useful for the realization of the remote infrared detectors. In the field of the temperature measurements there are well known sensors which operation is based on the variation of the electrical resistance of the sensitive material due to the temperature variation. Mostly precise between these types of sensors are the platinum resistance thermometers. The disadvantages of the existing devices are following: nonlinearity, large dimensions, necessity of electronic devices for the bridge completion and for the signal amplification, low level of output signal. Also well known are the devices with electrical resistance dependent from the temperature, or thermistors, deposited on ceramic substrate; they have an elevated sensibility but also high nonlinearity. low precision and a narrow operating range of temperature. In the field of the remote detectors there are currently bolometers with elevated sensibility; the disadvantages of such devices are elevated manufacturing cost and the necessity of a cooling to cryogenic temperatures. Comparing with temperature sensors currently available on the market, the new sensor has various advantages, between which the main ones are: 1. elevated sensibility 2. miniaturization of the probe (the maximum external diameter ap 3 millimeter) 3. elevated output electrical signal (1 mV/K @ I
_in
= 0.5 mA), that permits to work without the use of electronics and on long lines in industrial systems. 4. elevated linearity in a wide range of measurement 5. fast response 6. technological reproducibility 7. affordable manufacturing costs.