A thermistor sensor is an economical means of precisely sensing heat over a limited range of temperatures. A thermistor is a Highly sensitive to small changes in temperature, fairly accurate, metal oxide whose change in resistance is typically an inverse function of the change in temperature.
An excitation current is passed across the sensor and the voltage, which is proportional to the resistance, is measured and converted to units of heat calibration.
Since thermistor sensors usually have a large base resistance and a large change in resistance per unit of temperature change, compensation for lead wire length is not generally needed.
Thermistor Sensor vs RTD Sensor
This sensor is a type of resistor whose resistance varies significantly with temperature, more so than in standard resistors. Thermistors differ from resistance temperature detectors (RTDs or RTD sensors) in that the material used in a thermistor is generally a ceramic or polymer, while RTDs use pure metals.
The temperature response is also different; RTDs are useful over larger temperature ranges, while thermistors typically achieve a higher precision within a limited temperature range, typically −75 °C to 500 °F. These sensors are mainly used for automotive purposes.
Compare heat sensor and temperature control options today. At Hi-Watt, we work with a range of thermocouple and thermistor sensor options and understand the pros and cons of each type. Explore the differences between these temperature measurement devices today to find the best solution for your application today.
Thermistor vs Thermocouple
You need a sensor that will offer the exact specifications you need. Here are some basic features to use when comparing these two sensor types:
- Accurate readings
- Stable sensor design
- Durable packaging
- Rapid response times
- Acceptable temperature range
- Proper noise immunity
Use these features and your specific application to determine the ideal option. When in doubt, work with Hi-Watt to find which sensor option will offer you dependable readings.
Explore the differences in common industrial applications. While thermistors typically offer a more accurate temperature measurement, thermocouples are capable of handling larger temperature ranges. These are the most basic differences, but learn more about each sensor option to more accurately compare temperature readers for your application.
Typically made of sintered semiconductor materials, negative temperature coefficient, or NTC, thermistors use a mix of metal oxides to allow current flow. The thermistor measures the change in resistance that is proportional to the change in temperature.
High resistance in this type of thermistor occurs at low temperatures, and the resistance decreases as the temperature increases. This allows a quick, accurate reading of temperature changes.
Calibrating the resistance and temperature of an NTC thermistor requires the thermistor beta formula. Once properly calibrated and linearized, the information from this type of sensor can be used in temperature applications between -50 degrees Celsius and 250 degrees Celsius.
Choose the type of NTC thermistor to discover the many applications for this sensor option. Here are just a few probe assembly styles you can choose for your industrial application:
- Surface mount
- Glass encapsulated
Use these sensors for medical, aerospace, automotive, energy and HVAC applications. Most processes use NTC thermistors to determine temperature characteristics based on resistance, but these sensors can also be used to measure voltage-current and current-time information.
Hi-Watt, Inc. carries a wide range of thermistor sensors by top brands including Watlow and others. We also carry thermocouples, PID controllers, infrared heaters and more. Contact us today for all your industrial electric heater needs, we are here to help!