Temperature Sensors 2018-12-21T12:23:29+00:00

The PT100 is used for precise temperature monitoring applications where errors in measurement must be excluded. The linear relationship of the resistor to temperature simplifies its use in many applications. The precision of the PT100 allows its universal use for temperature monitoring, control and switching in windings, bearings, machines, motors, transformers and many other related applications. The PT100 sensor is a temperature dependent component. The resistance of the sensor rises linearly with temperature. The advantages are very precise measuring,+/-0.5c with a short response time.

KTY Sensors

These sensors display a virtually linear temperature coefficient over their entire range ensuring highly accurate measurements. As the coefficient is positive the sensors exhibit fail safe operation when a system overheats. Furthermore, silicone is inherently stable so KTY sensors are extremely reliable and have a very long operational life.

The KTY-84-130 sensors are generally coloured brown/white and the KTY-83-110/122 is green/yellow and 1000Ω @ 100°C or 600Ω@ 25°C. The operating range is from -40° to +300°C. The brown/white is generally used by Siemens and ABB where the green/yellow is used by Lenze. The polarity of the sensor is important as the unit will not operate accurately if incorrect. The sensor must be connected to a suitable controller.

Brown is positive and white is negative. Green is positive and yellow is negative. The KTY-83-110/122 is 1000Ω @ 25°C and operates from -55°C to + 175°C.

Thermal Cut Out/In

A temperature influenced bi-metal disk will open or close a circuit when the required temperature is reached. Suitable for internal or external use.  Where the unit is to be varnished in a VPI tank a special type of cut in must be used. Available in 10deg increments from 120 to 160°C.


A thermistor is a resistor whose resistance changes significantly with a change in temperature. The bead is generally manufactured from doped titanium which is stable in most applications. There are two types, NTC which is negative temperature coefficient and the resistance decreases with temperature or a PTC which is a positive temperature coefficient  and the resistance increases with temperature.

PTC Thermistors for the thermal protection of electrical machines, is a temperature dependent component. The rated operating temperature (ROT) corresponds to the curie point temperature of the ceramic. The resistance, of the PTC thermistor, rises very steeply with relatively small increases in temperature, thus triggering the switching function.

PTC Thermistors