Temperature sensor

A temperature sensor is a measuring device that converts temperature changes into usable output signals, widely used in industrial, medical, environmental monitoring, and other fields.
‌Basic Definition and Classification‌
The core function of a temperature transducer is to sense temperature and convert it into electrical or other readable signals. Based on the measurement method, it can be divided into two main categories:
Contact Sensors‌: Require direct contact with the measured object, such as thermocouples, thermistors (NTC/PTC), platinum resistance sensors (PT100), etc. They offer high accuracy but are limited by the characteristics of the measured object.‌‌
Non-contact Sensors‌: Measure temperature remotely through principles like infrared radiation, such as infrared temperature sensors. They are suitable for moving objects or high-temperature environments, with typical products like the SMTIR9901 series.‌‌
Working Principles‌
Different sensors achieve temperature measurement based on the following physical effects:
‌Metal Expansion Principle‌: Bimetallic strips bend due to temperature changes, generating signals.‌‌
‌Resistance Change‌: For example, PT100 utilizes the linear change of platinum resistance with temperature, while NTC exhibits a decrease in resistance value as temperature rises.‌‌
‌Thermoelectric Effect‌: Thermocouples generate a potential difference through temperature gradients.‌‌
Infrared Radiation‌: The intensity of an object's thermal radiation is proportional to its temperature, converted into electrical signals via thermopiles.‌‌
Typical Applications‌
Industrial Control‌: PT100 is used for high-precision process monitoring, and smart temperature sensors enable networked remote monitoring.‌‌
‌Medical Field‌: Body temperature sensors quickly measure human temperature through thermal elements.‌‌
‌Environmental Monitoring‌: Infrared sensors are used for fire warnings or temperature detection in electrical equipment.‌‌