Infrared thermometers are increasingly widely used, more and more families will be equipped with infrared thermometers at home, but they also have the characteristics of relatively inaccurate temperature measurement, and are greatly affected by the environment and use. The correct use will explained in this article. Infrared thermometer includes infrared ear thermometer, infrared forehead thermometer and infrared imaging human surface thermometer, etc. The first two types are mainly involved in this article.

It is recommended to select infrared thermometer with formal identification and standard basis.

The infrared thermometer belongs to Class II medical device, and its operation must be registered and approved by the food and drug supervision and administration department and obtain the registration certificate. In China, the technical requirements of infrared ear thermometers should comply with the national standard GB/T 21417.1 Medical Infrared Thermometers - Part 1: Ear Cavity Type. In the United States, medical devices such as thermometers should comply with the FDA 510K standard, and in Europe, infrared thermometers should comply with the CE certification standard. In addition, it is not recommended to use industrial infrared thermometers to measure body temperature, since the temperature measurement error of industrial infrared thermometers is relatively large, it is with a general error of 1.5 ℃ to 2.0 ℃.

Correctly understand the technical characteristics of infrared thermometer.

Many consumers believe that the infrared thermometer has higher "technology" content and more accurate measurement than the traditional mercury thermometer. In fact, the accuracy of the infrared thermometer is poor. In the general temperature range, the error of mercury thermometer is 0.1 ℃, infrared ear thermometer is 0.2 ℃, and infrared forehead thermometer is 0.3 ℃. At the same time, the use of infrared thermometer is greatly affected by the environment and the method of use, which will cause greater errors.

The performance of the infrared thermometer will deteriorate, especially when it is used in places where a large number of people gather, it is recommended to calibrate it regularly. For household use, it can be compared with mercury thermometer regularly. When the error exceeds 0.5 ℃, it is recommended not to use it.

Use in strict accordance with the instructions

1. The infrared thermometer should keep the gun head clean. Do not touch the skin of the tested person when using. If the gun head sensor is contaminated, clean it according to the instructions. Ear thermometers with probe earmuffs should keep the earmuffs clean and cannot be replaced by other brands of earmuffs or plastic wrap.

2. Keep the measured skin clean during measurement. Before the measurement, the subject should wipe off sweat and sebum, keep the measurement site clean and dry, and free of hair, dust, and obstructions.

3. The measuring position shall be accurate. When measuring the ear thermometer, insert the probe (with earmuff) into the ear canal, and stretch the ear according to the instructions to keep the ear canal straight. When measuring, the thermometer should be aligned with the center of the forehead area of the subject (the position slightly above the middle of the two eyes) and keep it verticall.

4. The measuring distance shall be appropriate. According to the distance requirements specified in the manual, the measurement results are easy to be inaccurate if the measurement is too close or too far.

5. The measurement results shall be verified. Using multiple measurements can improve the reliability of the data. Repeat the measurement twice within 1 minute, and the difference between the two measurements is not more than 0.3 ℃, so the data is reliable;

6. The thermometer shall be disinfected after measurement. After measurement, wipe with slightly wet medical alcohol gauze or alcohol cotton ball for disinfection.

Use correct body temperature criteria

The normal body temperature varies slightly from different measuring positions of the human body. The following table shows the normal body temperature range at different measuring positions of the human body for reference.

Note: The temperature measured by the infrared thermometer is divided into two types. One is the surface temperature, which reflects the actual temperature of the skin of the tested part. The ear temperature is generally the surface temperature; The other is to estimate the temperature, which is to convert the skin surface temperature of the measured part into the core temperature or approximate temperature of the human body (such as oral temperature). Most of the thermometer displays the estimated temperature.

Reduce the influence of environmental temperature factors on measurement accuracy

When using infrared thermometer, pay attention to the environmental conditions to meet the requirements of measuring equipment. The rated working environment temperature of infrared thermometer is generally 16 ℃~35 ℃, and the outdoor temperature is low in winter, with strong convection, radiation, large temperature fluctuation and other effects, so it is not suitable use in cold weather.

If it is necessary to use infrared thermometer in outdoor environment, the possible error caused by it should be considered. It is recommended to select 3 to 5 persons with normal body temperature for sampling, use mercury thermometer to measure the armpit and infrared thermometer to measure the forehead respectively, compare the temperature, and correct it in the subsequent measurement.

During outdoor measurement, it is also necessary to consider the environment of the measured personnel. When measuring the temperature of the personnel in the vehicle in winter, the temperature will be too high due to the heating. In the outdoor environment in winter, measuring the wrist temperature can better reflect the actual body temperature than measuring the frontal temperature.