1. What is the normal body temperature of the forehead thermometer?
Generally speaking, the normal body temperature of the human body is in the range of 36℃ to 37℃, and the body temperature has been decreasing in recent years. According to the different measuring instruments and measuring parts, the measured normal body temperature also varies:
The temperature of the forehead is generally about 35.8℃ to 37.8℃, the temperature of the armpit is usually 36℃ to 37℃, and the oral temperature is typically measured. The obtained normal body temperature is in the range of 36.3 ℃ to 37.2 ℃, the normal temperature of the anus is 36.6 ℃ to 37.8 ℃, and the eardrum temperature measured with an ear thermometer is normally 35.8 ℃ to 38 ℃.
Even with normal operation, there will still be a certain error in measuring body temperature with the forehead thermometer—approximately ±0.1-0.3 ℃. Therefore, if the measured body temperature is slightly higher or lower, don’t worry. You can measure it several times, and if the body temperature remains abnormal after multiple measurements, it is necessary to use a more accurate mercury thermometer or go directly to the hospital.
2. What are the reasons for the inaccurate measurement of the forehead thermometer?
Wrong Use Method:
Forehead thermometer measurement generally requires the device to be aimed at the forehead of the human body and measured at a distance of 3-5cm. If the distance is too close or too far, it will cause a large measurement error.
Mode Not Set:
Some forehead thermometers have two functions: surface temperature and body temperature. Choosing the wrong one may result in an exception. Additionally, some forehead thermometers offer two units of Fahrenheit and Celsius, and the difference between the numbers is relatively large. Therefore, if you get data in the range of eighty or ninety degrees, it may be set to Fahrenheit mode.
Other Interference Factors:
The forehead thermometer tests the forehead, which is easily affected by external factors such as sweat, dirt, dust on the forehead, and hair occlusion. Moreover, the forehead thermometer operating in an environment with wind or a large temperature difference between indoor and outdoor can also lead to significant errors.
Instrument Damage:
The forehead thermometer is not resistant to heavy falls and collisions. If it is broken, it will be inaccurate. In such cases, it is recommended to return the product to the factory for repair or directly replace it with a new one.
3. How to calibrate the infrared forehead thermometer?
If the infrared forehead thermometer is inaccurate, it can be calibrated according to the “Infrared Thermometer for Measuring Human Body Temperature” Specifications (JJF 1107-2018) at the legal metrology technical institution. If the error is still large or the test is unstable after calibration, it is recommended to stop and replace the forehead thermometer with a new one.
In addition to calibration at the calibration institution, if there is an error in the use process that needs calibration, you can test it several times after eliminating interference factors. Alternatively, measure the normal body temperature once after the test subject takes the measurement. Another method of calibrating the forehead thermometer is to “keep warm” for the device. Since the forehead thermometer cannot work in a low-temperature environment or has a large working error, it can be placed in a dry incubator to keep warm. Alternatively, place the forehead thermometer in the measurement environment for 20-30 minutes, allowing the temperature to adapt to the environment before measuring.