A thermistor is a type of temperature sensor. They are very small, relatively cheap and give a very quick response to temperature change.
Thermistors consist of a small bead resistor and two wires which can be connected to an electrical circuit, a change in temperature will mean there is a change in resistance in the resistor which can be detected and measured by the electrical output of the circuit.
Thermistors are very diverse and are often used for voltage regulation, time delays, circuit protection and volume control.
There are two main types of thermistor; Negative Temperature Coefficient thermistors (NTC) or Positive Temperature Coefficient (PTC) most of the thermistors which we supply are NTC Thermistors, PTC’s are part of our product range also.
With an NTC Thermistor, when the temperature increases, the resistance decreases.
Conversely when the temperature decreases, the resistance increases.
A PTC Thermistor works differently; when the temperature increases, the resistance increases and similarly when the temperature decreases, the resistance also decreases.
Thermistor Applications
Due to them being available in a variety of sizes and being simple to use, thermistors are used in a range of applications across different industries
Thermistor Applications - Domestic (White Goods)
Thermistors are very common and you may be surprised to know the amount of appliances within a home environment which use thermistors to monitor and measure temperature. Some of these applications are;
Microwaves/ Boilers - thermistors monitor the internal temperature and ensure it doesn't become too hot
Circuit protector - thermistors control surges of power and ensure the correct amount is being pushed through device which are plugged in
Digital thermometers - thermometers often use thermistors as the temperature sensing element as they have a fast response and are accurate.
Thermistor Applications - Commercial
Vehicle cabin heat - to ensure the vehicle stays at the correct temperature thermistors are often used
Manufacturing - thermistors are used as a “circuit breaker” in manufacturing facilities; if the temperature becomes dangerously high the thermistor will cause the circuit to break.
HVAC refrigeration applications - thermistors are used to measure building and control processes. This increases control and efficiency.
3d printers - thermistors are used to regulate temperatures as they must be controlled precisely
Medical applications - when precise temperature monitoring is essential, a thermistor is used as it is highly sensitive and will detect if the temperature changes just a tiny amount. They are used for catheters, patient monitoring and dialysis equipment
Food & Beverage Industry - thermistors can be used to monitor the temperatures within the environments of the handling and processing of food/ beverage to ensure it is kept at the correct temperature.
Thermistors from Variohm
Variohm is a sister company of Acal BFi.
Our range of NTC Thermistors are either glass or epoxy coated making them reliable in a range of environments. They are available in different dimensions and tolerances.
For more information on our thermistors or on any of the products in our range please contact us.
