Thermistor technology

NTC (negative temperature coefficient) temperature sensor is a temperature measuring element that uses the exponential decrease in the resistance of a thermistor as the temperature rises. Its core is a ceramic semiconductor made by sintering metal oxides (such as manganese, cobalt, and nickel), and the temperature is inferred by measuring the change in resistance. The following are its core technical characteristics, applications, and selection points:

There are four main temperature sensors used today in modern-day electronics: Negative temperature coefficient (NTC) thermistors, resistance temperature detectors (RTDs), thermocouples, and semiconductor-based integrated (IC) sensors.

When selecting a thermistor, it is indeed necessary to comprehensively consider many key parameters and packaging (epoxy resin Encapsulation, Glass Bead Encapsulation, thin film Encapsulation, SMD Encapsulation, stainless steel probe sensor Encapsulation, injection molding coating). Let me tell you in detail:

‌ The resistance range of thermistors is wide, and the resistance of NTC thermistors can range from tens of ohms to ten thousand ohms, and even special devices can be customized according to needs. Commonly used resistance values ​​are 2.5Ω, 5Ω, 10Ω, etc., and common resistance errors are ±15%, ±20%, ±30%, etc. The resistance range of PTC thermistors is usually from 1KΩ to hundreds of KΩ.

‌Reasonable arrangement of temperature sensors‌: The location and arrangement of temperature sensors will also affect the response time. If the contact area between the sensor and the object being measured is large, the heat exchange will be faster and the response time will naturally be shorter. However, please note that too large a contact area may also lead to increased measurement errors, so we have to make a trade-off based on the actual situation.

As a component that can change the resistance value according to temperature changes, thermistors have a wide range of applications (such as temperature measurement, temperature control, temperature compensation, temperature alarm, battery thermal protection). Let me share with you several application cases of thermistors:

The connection method of the NTC thermistor temperature sensor needs to be determined according to the actual application scenario and measurement requirements. During the wiring process, be sure to pay attention to the pin polarity, wire selection, temperature range, filtering and decoupling, grounding treatment, and verification and calibration to ensure the accuracy and reliability of the measurement.