Popular science knowledge of human infrared thermometer
The infrared thermal imaging body temperature rapid screening device can monitor large areas in crowded public places, automatically track and alarm high-temperature areas, and cooperate with visible light video to quickly find and track people with high body temperature. When the infrared thermal imaging body temperature rapid screening instrument integrates technologies such as face recognition and mobile phone probes, it can also grasp more information about people with higher body temperatures.
Infrared thermometers can be divided into infrared ear thermometers and infrared forehead thermometers. Infrared thermometers are simple in equipment, easy to use, and affordable. The application can realize sequential and rapid temperature measurement of personnel.
Principle and measurement method
The heat of the human body will be dissipated into the environment in the form of thermal radiation. The human body infrared thermometer detects the thermal radiation of the human body through the built-in sensor, so as to achieve the purpose of measuring body temperature.
The infrared thermal imaging body temperature rapid screening instrument uses infrared temperature measurement technology to quickly measure the surface temperature of the human body in a non-contact manner. It is an instrument that warns when the measured temperature reaches or exceeds the preset warning temperature value.
Infrared ear thermometer is an instrument that uses the infrared radiation exchange between the ear canal and tympanic membrane to measure body temperature; it measures the tympanic membrane of the human ear, the ear canal should be cleaned before measurement, and the probe should be inserted into the ear hole for measurement, and a hygienic ear thermometer must be equipped. Use it in sets to avoid cross-infection when multiple people use it.
Infrared forehead thermometers are instruments that measure skin temperature using infrared radiation exchange between the skin and the detector and appropriate emissivity corrections. The measurement is on the forehead of the human body. Point the temperature gun at the center of the forehead. If there is sweat, wipe it off. The distance from the forehead is recommended to be 1-3 cm.
Precautions for use
The advantages of infrared temperature measurement: First, there is no contact with the measured object, and unnecessary infection will not be caused when measuring body temperature; second, it is fast, usually the measurement time is less than 1 second, and generally does not exceed 2 seconds. Therefore, it is very suitable for application in the prevention and detection of fever diseases.
Usually, when the human body temperature is around 37°C, the accuracy of the infrared thermal imaging body temperature rapid screening instrument can reach ±0.3°C, and the infrared thermometer can reach ±0.2°C.
In terms of measurement accuracy, the infrared ear thermometer has the highest measurement accuracy, followed by the infrared forehead thermometer. However, if the measurement method is not correct, the measurement results will also be inaccurate. For newly purchased human infrared thermometers, or when they are used frequently and have doubts about the measurement results, the human infrared thermometer should be calibrated to determine its correction value, which can eliminate the systematic error of the thermometer as much as possible.
The blackbody radiation source can be used to calibrate the human body infrared thermometer. Its effective emissivity and temperature control stability have higher requirements. The blackbody temperature is usually measured with a contact thermometer such as a platinum resistance thermometer or a liquid-in-glass thermometer, and its temperature is compared with the value measured by an infrared thermometer to obtain a calibration value. The black body for calibrating the infrared ear thermometer also needs to design its opening shape and size specially according to the requirements of the thermometer to be tested.
