A basic infrared temperature sensor, also known as an infrared thermometer or IR thermometer, measures the temperature of an object by detecting the infrared radiation emitted by the object. All objects with a temperature above absolute zero (-273.15°C or -459.67°F) emit infrared radiation as a result of their thermal energy.
Here's how a basic infrared temperature sensor works:
Emission of Infrared Radiation: As an object's temperature increases, its atoms and molecules gain kinetic energy and vibrate more intensely. This vibration causes the emission of electromagnetic radiation in the form of infrared light. The intensity and spectrum of this radiation are determined by the object's temperature.
Infrared Sensor: The IR thermometer contains a sensor, typically a thermopile or an infrared detector, designed to detect the infrared radiation emitted by the object. The sensor is sensitive to a specific range of infrared wavelengths.
Optics: The IR thermometer also has an optical system that focuses the infrared radiation from the object onto the sensor. This optical system can include a lens or a mirror to ensure that the infrared radiation from the object reaches the sensor accurately.
Temperature Calculation: The sensor detects the intensity of the infrared radiation emitted by the object and converts it into an electrical signal. This signal is then processed by the thermometer's internal electronics to calculate the temperature of the object. The calculations are based on the Stefan-Boltzmann law, which relates the temperature of an object to the intensity of its emitted radiation.
Calibration: To provide accurate temperature readings, IR thermometers are often calibrated using known temperature references. The internal electronics of the thermometer are adjusted so that they correspond correctly to the detected infrared radiation levels and provide accurate temperature readings.
Display or Output: The calculated temperature is then displayed on the thermometer's screen or output in a digital or analog format, allowing the user to read the temperature of the measured object.
It's important to note that the accuracy of the temperature measurement can be affected by various factors such as the distance between the sensor and the object, the emissivity of the object's surface (which determines how efficiently it emits infrared radiation), and the presence of any obstructions or ambient temperature variations in the surroundings.
Basic infrared temperature sensors are commonly used in a wide range of applications, from industrial and scientific measurements to medical and home use.