A basic infrared temperature sensor, often referred to as an infrared thermometer or IR temperature sensor, measures the temperature of an object by detecting the infrared radiation it emits. All objects with a temperature above absolute zero (-273.15°C or 0 Kelvin) emit infrared radiation in the form of electromagnetic waves. The intensity and wavelength of this radiation depend on the object's temperature.
Here's a simplified explanation of how a basic infrared temperature sensor works:
Emission of Infrared Radiation: When an object is at a temperature above absolute zero, it emits infrared radiation. The intensity and spectrum of this radiation are determined by the object's temperature.
Optical System: The infrared temperature sensor has an optical system that focuses the emitted infrared radiation onto a detector. This optical system might include lenses and filters to ensure accurate and targeted measurements.
Detector: The detector used in these sensors is sensitive to infrared radiation. Common types of detectors include thermopiles and bolometers. When infrared radiation strikes the detector, it generates a small electrical signal proportional to the intensity of the radiation.
Signal Processing: The electrical signal from the detector is then processed by electronics within the sensor. This signal processing might involve amplification, filtering, and calibration to convert the electrical signal into a temperature reading.
Reference Temperature: Some infrared temperature sensors have a built-in reference temperature sensor, typically a thermistor or other temperature-sensitive component. This reference sensor measures the ambient temperature of the sensor itself. This reference temperature is used to compensate for any temperature differences between the sensor and the measured object.
Emissivity Correction: Emissivity is a measure of how efficiently an object radiates infrared energy compared to a perfect blackbody radiator. Since most real-world objects are not perfect blackbodies, the sensor might allow you to adjust the emissivity setting based on the material properties of the object being measured.
Display or Output: The final temperature reading is usually displayed on a digital screen or output as an electrical signal (analog voltage or digital communication) that can be read by a computer or control system.
It's important to note that while this explanation provides a general understanding of how basic infrared temperature sensors work, the actual implementation and technology might vary among different sensor models and manufacturers. More advanced sensors can incorporate additional features like adjustable focus, laser pointers for aiming, and connectivity options for data logging and analysis.