As a common sensor, temperature sensor plays an important role in industrial control, electronic equipment, automotive industry and other fields. Its working principle is mainly to convert the temperature into the corresponding electrical signal output by using the correlation of the material when the temperature changes. There are various classifications of temperature sensors. According to different working principles and application scenarios, temperature sensors can be divided into two categories: contact and non-contact temperature sensors, which cover many specific types.
working principle:
1. Contact temperature sensor:
◆ Thermistors (PTC, NTC): Thermistors change with temperature CD4052BCN There are two common resistance values: positive temperature coefficient (PTC) and negative temperature coefficient (NTC). When the temperature increases, the resistance value of the positive temperature coefficient increases; The negative temperature coefficient is opposite.
◆ Thermocouple: It is composed of two different metal wires welded together. Temperature change is measured according to the generated electromotive force caused by temperature change. It has high precision and is commonly used for high temperature measurement.
◆ RTD (resistance temperature detector): use the characteristic that resistance is proportional to temperature to measure the temperature indirectly by measuring the change of resistance value, usually using platinum or nickel as the sensing element.
2. Non contact temperature sensor:
◆ Infrared temperature sensor: measure the temperature of the target object by sensing the infrared energy radiated by the object. It is suitable for temperature measurement without contact, and is commonly used in household thermometers.
◆ Acoustic temperature sensor: According to the relationship between sound propagation speed and medium density, the temperature is calculated by the propagation time of sound waves, which is suitable for temperature detection in high temperature and high pressure environments.
◆ Microwave temperature sensor: determine the temperature of objects by measuring the frequency change of microwave radiation, which is suitable for occasions requiring large-scale and continuous temperature monitoring.
Main classification:
1. Contact temperature sensor:
◆ Thermistor sensor: common ones are platinum resistance, copper thermistor, etc., with wide measurement range, fast response speed and high precision.
◆ Thermocouple sensor: It can work stably in high temperature environment, with good linear characteristics and stability.
◆ RTD sensor: full name of resistance temperature detector, high precision, suitable for precise temperature measurement.
2. Non contact temperature sensor:
◆ Infrared temperature sensor: it can measure without touching objects, and is suitable for occasions requiring remote and rapid temperature measurement.
◆ Laser temperature sensor: similar to infrared principle, but more accurate and accurate positioning, suitable for high-precision measurement in industrial production process.
◆ Infrared thermal imager: it can realize thermal imaging of the whole area, quickly capture hot spots, and play an important role in fault detection, security monitoring, etc.
To sum up, temperature sensors play an important role in modern industry and life. Their working principles and classifications are diverse. Users can select suitable temperature sensor types according to specific application needs to achieve accurate temperature measurement and control.
