Thermistor For Body Temperature Measurement

It could be used for human body temperatures but it depends on how you want to measure the body temperature.

Thermistor for body temperature measurement. The temperature measurement of the surface of the body can be accomplished using different sensors. Temple and forehead type thermometers use the same technology to measure infrared radiation as ear type thermometers they just measure it from a different location on the body. However ptc thermistors have a sort of tipping point and greatly change the resistance at some temperature. For this reason for most low cost temperature measurement ntc thermistors are preferred.

The silicone oil provides a very uniform temperature so many devices can be calibrated in a single cycle. Thermistors differ from resistance temperature detectors rtds in that the material used in a thermistor is generally a ceramic or polymer while rtds use pure metals. Convert the temperature values to kelvins and invert. Avoid dewing and condensation unless thermistor is specified for these conditions.

Take the corresponding measured resistance values and compute the natural logarithm. Since the human skin acts as a thermal insulator the temperature of the skin isn t an accurate representation of actual body temperature. The thermistor used in this article is mainly used for sensing environmental temperatures. Types of sensors like ntc negative thermal coefficient thermistors thermopiles and digital temperature sensors.

It is relatively easy to calibrate your own response curves if you have an accurate temperature measurement standard. The adt7422 has an accuracy of 0 1 c over a temperature range of 25 c to 50 c. The thermistor measures the cold junction temperature of the thermopile and both the thermopile and thermistor measurements are used to calculate the body temperature. Measurement purposes checking the specified resistance vs.

Temperature the component must not be immersed in water but in suitable liquids e g. Perfluoropolyethers such as galden. Te connectivity te manufactures ntc negative thermal coefficient thermistors thermopiles and digital temperature sensors to support the wide range of accuracy packaging and performance conditions amongst the different. This temperature range is centered around the typical human body temperature of 38 c making the adt7422 ideal for accurate vital signs monitoring.

This makes the ptc thermistor a little harder to interface with. The typical operating temperature range of a thermistor is 55 c to 150 c though some glass body thermistors have a maximal operating temperature of 300 c.