Thermistors: Sensitive Temperature Detectors
Thermistors act like microscopes in the world of temperature, excelling at capturing minute changes. These sensors work by detecting changes in resistance with temperature, and there are two common types:
NTC (Negative Temperature Coefficient): Resistance decreases as temperature increases, suitable for a range of -50°C to 150°C.
PTC (Positive Temperature Coefficient): Resistance increases as temperature increases, often used for overheat protection.
Advantages include fast response and high accuracy, but a relatively limited measurement range.
Thermocouples: High-Temperature Veterans in Industry
Thermocouples are considered the steel warriors of temperature measurement, made by welding two different metals together. When a temperature difference exists between their ends, a voltage signal is generated (Seebeck effect). Characteristics include:
Ultra-wide measuring range: Some models can measure from -200°C to 2300°C.
Simple structure: No easily damaged parts, resistant to mechanical shock.
Rapid response: Suitable for dynamic temperature monitoring.
Disadvantages include a relatively weak signal, requiring a dedicated amplifier.
Infrared Sensors: Non-Contact Temperature Measurement Experts
Infrared temperature sensors act like telescopes in the world of temperature measurement, measuring surface temperature without contact with the object. They operate based on the infrared radiation emitted by the object. Typical applications include:
Temperature measurement of moving objects (e.g., production lines).
Hazardous environments (high-voltage electrical equipment).
Places with high hygiene requirements (food processing).
