What are the types of temperature sensors?

Release Date:

2022-07-28

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1. Thermocouple sensor

A thermocouple is a temperature-sensing element and an instrument. It directly measures temperature and converts the temperature signal into a thermoelectric potential, which is then processed by an electrical meter (a secondary instrument) to determine the temperature of the measured medium. The fundamental principle of thermocouple temperature measurement is that two conductors made of different materials form a closed circuit; when a temperature gradient exists between the two junctions, a current flows in the circuit, and an electromotive force—known as the thermoelectric potential—is generated. This phenomenon is referred to as the Seebeck effect.

2. Thermistor sensor

The primary component of a thermistor sensor is the thermistor. When thermal radiation is present around the thermistor material, it absorbs the radiant heat, causing its temperature to rise and resulting in a change in the material’s resistance.

3. Resistance Temperature Detector (RTD)

RTDs are typically made from platinum, copper, or nickel. The resistance–temperature relationships of these metals are shown in the figure; they exhibit large temperature coefficients, respond rapidly to temperature changes, resist thermal fatigue, and are readily fabricated into precision coils.

RTD is currently the most accurate and stable. Temperature sensor Its linearity is superior to that of thermocouples and thermistors. However, RTDs are also slower to respond and relatively more expensive temperature sensors. Consequently, RTDs are best suited for applications where high accuracy is critical, while speed and cost are less important considerations.

4. IC Temperature Sensor

(1) Analog Integration Temperature sensor

Integrated sensors are fabricated using silicon semiconductor integration technology, and are therefore also referred to as silicon sensors or monolithic integrated temperature sensors. Analog integrated temperature sensors emerged in the 1980s; they are dedicated ICs that integrate a temperature sensor onto a single chip, enabling both temperature measurement and analog signal output. The key features of analog integrated temperature sensors include single-functionality (limited to temperature measurement), low measurement error, low cost, fast response, long transmission distances, compact size, and ultra-low power consumption, making them well suited for remote temperature sensing and control. They also eliminate the need for nonlinear calibration and require only simple external circuitry.

(2) Digital Output Sensor

Number Temperature sensor It emerged in the mid-1990s, representing the culmination of microelectronics, computer, and automated test equipment (ATE) technologies. Today, a variety of smart temperature sensor product families have been developed worldwide. Each smart temperature sensor integrates a temperature sensor, an A/D converter, a signal processor, memory (or registers), and interface circuitry. Some models further incorporate multiplexers, a central processing unit (CPU), random-access memory (RAM), and read-only memory (ROM). Smart temperature sensors are characterized by their ability to output temperature data and associated control signals, making them compatible with various microcontrollers (MCUs). Moreover, their testing functions are implemented through software running on top of hardware, and their level of intelligence and functionality is largely determined by the sophistication of the software development.

Huizhou Jin Yuan Xiang Electronic Co., Ltd. is a high-tech enterprise that manufactures temperature and humidity sensors. Temperature sensor Widely used in small household appliances, industrial temperature measurement, and other environments.