What are NTC Thermistors used for?
NTC Thermistors are probably the most common established form of temperature sensor used by engineers in today’s commercial products – from industrial machinery, medical devices and domestic appliances to battery packs and electric vehicles.
Whilst the choice of sensors available to engineers is extensive, once parameters and applications are reviewed, ATC’s technical sales team will recommend the best temperature sensor fit for your application.
What is an NTC Thermistor?
Thermistor is a portmanteau of “thermal” and “resistor”, while the acronym NTC denotes Negative Temperature Coefficient, where the thermistor resistance falls as the temperature rises. Temperature sensitive with a clearly defined characteristic, these solid-state sensors are, in effect, variable resistors.
There are two initial parameters which help define an NTC thermistor:
- R25 nominal resistance at 25°C. 10kΩ is the most widely used value.
- B Value (or Beta Value) describes the shape of the resistance curve, usually specified between 25°C and 85°C.
Fix those two figures first and you are half-way to specifying the component you need. The remainder comes down to tolerances, form-factor and the environment being measured (covered later in this page).
Why are NTC Thermistors so popular?
- Ideal for measuring temperatures from -60°C up to 350°C
- High accuracy down to ±0.5% (±0.2°C or better)
- Very steep T.C.R. (Temperature Coefficient of Resistance)
- Available in multiple forms/packages for easy integration
- Affordable and reliable
What are NTC Thermistors Used For?
Broadly speaking, NTC thermistors find applications in temperature control, temperature compensation and temperature measurement. Extremely accurate and highly versatile, they are found in a wide range of applications:
Batteries
NTC thermistors play a key role in the monitoring of battery cell temperatures as part of battery management systems. As the technical demands on rechargeable batteries have accelerated to reflect end-product performance, NTCs have also evolved – into smaller, faster and more responsive sensors within improved housings for ease of installation.
From tiny, thin-film FT series NTCs to 1000V rated ring sensor assemblies, our NTCs are designed for use in battery applications within medical, transport and robotic industries. In particular, their use in the rapidly developing e-mobility market (fast-charging systems, battery monitoring/optimisation, battery coolant and power IGBT sensing/control) demands accurate and responsive NTC thermistor sensors providing optimum performance and critical safety.
Industrial & Manufacturing Equipment
NTC thermistor sensors appear right across industry: flexible heating elements, plastic laminating machines, soldering irons, hot glue guns, photocopiers, laser printers and smoke and fire detection. They are equally common in laboratory and calibration equipment, from chemical analysis and titration through to spectrophotometry, anemometry and bolometry, where accuracy matters more than outright range.
Two selection factors dominate industrial work:
- Operating temperature. Where the process runs hot — soldering, laminating, adhesive application — glass-encapsulated NTC thermistors extend the usable range well beyond what epoxy-coated NTCs can tolerate.
- Response time. When industrial processes move quickly, fast response temperature probes’ low thermal mass gives you the temperature control that bulkier sensors cannot.
Medical Devices
Patient monitoring, wearable devices, digital thermometers, dialysis equipment, incubators and respiratory devices all rely on accurate, compact temperature sensing. Medical device temperature sensors carry some demands that industrial parts don’t have to meet: biocompatibility and tight interchangeability tolerance, so that units can be built and replaced without individual calibration.
Domestic and consumer appliances
Within the domestic environment, NTCs are used everywhere for temperature control and ambient air monitoring; room thermostats, washing machines, tumble driers, dishwashers, fire detectors, electric showers and hair/personal care appliances.
There are NTC thermistors to suit nearly every possible application, and ATC Semitec have the leading range of reliable, high-performance sensors in fully customisable designs. We have an NTC thermistor to suit all situations.
Contact ATC Semitec on 01606 871680 and we will walk you through the options and find the right thermistor solution for you.
How to choose the right NTC thermistor
Most thermistor specifications come down to seven parameters. Working through them in order will usually help get you to a shortlist of two or three suitable sensors.
| Consideration | What to decide | Where it points |
|---|---|---|
| R25 Value | Nominal resistance at 25°C — must suit your circuit. 10kΩ is one of the most common values. | All NTC ranges |
| B Value | Determines curve shape and sensitivity across your working band. | All NTC ranges |
| Tolerance | Whether you need interchangeability without per-unit calibration. | Precision NTC thermistors |
| Temperature Range | Encapsulation sets the ceiling — epoxy for moderate, glass for high temperature. | Glass high temp NTC thermistors |
| Response Time | Lower thermal mass means a faster response but possibly less robustness. | Fast response temperature probes |
| Package & Mounting | Board-mount, flying leads or surface-sensing. | SMD chip / rigid lead / flexible lead and flexible film |
| Ingress Protection | Immersion, vacuum impregnation or condensation exposure calls for IP67 proof minimum. | Waterproof temperature sensors |
Where a standard part does not fit, most of our ranges are customisable on lead lengths, terminations, housings and calibration.
NTC thermistors from ATC Semitec
ATC Semitec stocks an extensive range of NTC thermistors: high accuracy, SMD, flexible lead, IP67 and fast response, with a large UK stock holding and next day delivery. With over 30 years’ technical experience our engineers can offer in-depth technical advice and support. ATC Semitec is ISO 9001:2015 certified.