Types of Thermistors

Thermistors are part of our temperature sensors product range. They are very compact and an accurate way of measuring temperature.

Thermistors measure temperature by using resistance. Different types are available to suit different applications.

NTC and PTC Thermistors

The two main types of thermistor are NTC (Negative Temperature Coefficient) and PTC (Positive Temperature Coefficient).

An NTC's resistance will decrease with temperature whereas the resistance from PTCs will increase. NCTs are the type most commonly used for temperature sensing applications - you can view our range here.

Thermistor Specifications

Resistance

Thermistors will often be described using their resistance value such as a 10K thermistor or a 5K thermistor, with the number representing the resistance value in Ohms. These numbers are often used to determine the best thermistor for any given application.

Axial, Radial or Chip

Thermistors have different styles; the most common two are radial or axial. Radial thermistors have both wires leaving the bead in the same direction. Axial thermistors have one wire coming out of the top and one at the bottom with the thermistor bead in the middle. Thermistor chips have no leads.

Glass or Epoxy 

The beads of thermistors are usually made out of either glass or epoxy. Epoxy thermistors are more suited to lower temperature applications whereas glass thermistors are usually used for higher temperature applications.

Applications for Thermistors

Because they are small in size, highly accurate and usually very good value for money, thermistors are widely used for temperature measurement. Some of the industries which use thermistors are;

• Medical applications  
• Aerospace applications  
• Automotive applications  
• Environmental monitoring  

For more information about thermistors or if you have any questions on the above, please contact us at 01327 351004 or sales@variohm.com