Thermistor Strings


Thermistor Strings have a negative temperature coefficient (NTC) where resistance decreases with rise in temperature. The NTC can be as large as several per cent per degree C, which allows the thermistor to detect minute changes in temperature.Thermistor Strings have a non-linear output that can be represented by the Stein-Hart Equation: T_c=1/(A+B(InR)+C(InR)^3 )-273.2 Where T is the temperature in degrees Centigrade and R is the resistance in ohms. HMA Geotechnical can supply thermistors singly or up to 32 per string covering temperature ranges from -20 to 80 °C on standard units or -30 to 230°C on the High Temp Range (HT) Also available is an addressable thermistor string that can be configured up to 248 sensors on a single 6mm diameter cable up to 2000m in length. Using a simple readout to a customised logging system we can also meet all your reading needs to get the information where and when you need it.