Hand-held infrared thermometer

At the gate of a community in Yuzhong District, the security guards measuring temperature of the people entering the community

At the Xiaoshizi Station of Line 1, the infrared temperature measurement system measuring the temperature of passengers

At a factory in Nan’an District, the security guardian taking the temperature measurement for personnel entering the factory

Schematic diagram of infrared thermometer receiver

CHONGQING (CQNEWS) -- During the period of epidemic prevention and control, many public places, units and communities use temperature guns to measure body temperature of people in and out. After being tested many times, many people began to pay attention to their body temperature. It’s 33.3 ℃!” Mr. Qi, from Nan’an suspected that he was a “cold-blooded animal”.

Is the thermometer accurate? Will the temperature measured outdoors change when it is cold or hot? Is the body temperature different for different ages and genders? See it in Chongqing Evening News reporter’s investigation.

Only 33.3℃?

Mr. Qin, 28, who lived in Changjiangcun, Nan’an District was in good health. Recently, every time he went out and returned to the community, the security guard will use an infrared thermometer to check his temperature. In recent times, his temperature was relatively low. His latest temperature is 35.3 ℃. It was once 33.3 ℃ before.

Ms. Shi from Haitangxi, Nan’an District, said that there was a section in the high school biology textbook about the temperature of the human body. The armpit temperature is 36.8 ℃, the oral cavity temperature is 37.2 ℃, and the rectal temperature is 37.5 ℃. Why is the forehead temperature so low now?

There will be some differences in different environments

The reporter inquired the manufacturer and Mr. Bu who was engaged in the trade service of temperature measuring gun in Chongqing about how the temperature measuring gun or thermometer worked.

According to Mr. Jiang, an employee of an electronic company engaged in the production of infrared thermometers in Shenzhen, Guangdong Province, at present, most of thermometers or temperature guns on the market are developed by using infrared technology, which can be used to test the temperature of objects and the temperature of the forehead, ears and wrists of the human body. Because of the characteristics of non-contact with human body and short measurement time, infrared thermometers are widely used in public places during epidemic prevention and control.

According to Mr. Bu, who is engaged in the trade service of temperature measuring gun in Chongqing, most of the infrared thermometers on the market belong to household and medical use. Although the infrared thermometers can measure the temperature quickly, they will be affected by the external environment. For example, if the temperature is low and the forehead is tested, the measured temperature will have a deviation. Generally speaking, the deviation temperature will be 0.2 ~ 0.5 ℃, if the temperature is too low, the deviation may still exist. It may be around 1 ℃. In general, the result of forehead test is more accurate in 25 ℃. If the outdoor temperature is low, you can choose to test the wrist or neck. If the forehead sweats after exercise, you should also wipe the sweat or wait for a period of time before measuring, and then the measured results are relatively accurate.

Minor changes are normal 

According to Liu Chunguang, chief physician of the Emergency Department Of the Army Specialty Medical Center, the normal temperature of armpit in our textbook is 36 ℃ ~ 37 ℃, so the average value will be about 36.5 ℃.

When measuring body temperature, factors such as test location, time, season and individual differences will affect the measurement results, so the measured body temperature can have minor changes in the normal range. For example, the temperature in the afternoon is relatively higher than that in the morning, but the difference is generally less than 1 ℃. Therefore, it is considered that the normal temperature cannot be simply expressed by number “37 ℃”.

Liu Chunguang said that in his daily work, the patient’s temperature is generally around 38 ℃; the normal temperature is generally around 36 ℃ to 37 ℃. In the fever clinic, the patients with high fever were 38 ℃ ~ 39 ℃. “When a patient goes to the fever clinic to see a doctor, whether he has taken his temperature outside the hospital with a temperature measuring gun or with an infrared temperature measuring instrument, the doctor needs to take a temperature measurement under the armpit so as to check again. If the patient’s temperature is above 39 ℃, we will monitor it every 2-4 hours.” He said that if the difference between the measured values is large, it is recommended to take a mercury thermometer retest.

In addition, the infrared temperature measuring instrument mainly receives the signal from the human body, and the machine itself does not emit infrared. So don’t worry about the harm of infrared thermometer.

Liu Chunguang reminds you to exercise properly, adjust your mind and have a balanced diet. Don’t get too involved in a temperature test. Being too nervous will affect your temperature as well. (Translated by Luo Juan, Fathom Language Limited)