There is no uniform standard for the infrared thermometer, then how to test it?

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Author : Joe Wong
Update time : 2020-10-13 10:52:26
There is no uniform standard for the infrared thermometer, then how to test it?

As companies resume work one after another, the demand for infrared thermometers has soared. However, the temperature measurement value has errors and the temperature measurement parts are inconsistent, and the subject is often covered by the entire process.

The reporter learned that there is currently no national standard for forehead infrared thermometers in China, and the industry has called for greater supervision of the industry, standardizing market access, and promoting the infrared thermometer industry to return to normal.

Big difference

Body temperature measured 33 degrees Celsius

Obviously it was the same person, and the temperature measured at the entrance of the unit was 36 degrees Celsius, but it dropped to 33 degrees Celsius at the gate of the community. At the entrance of the community, the temperature measured by the property for Mr. Lu surprised him: "33 degrees Celsius? Am I going to get cold!"

Mr. Lu said that the forehead infrared thermometers used in residential properties never seem to be very accurate. “It is common to measure a body temperature of 35 degrees Celsius, and it is rare that it can reach 36 degrees Celsius. This is even more exaggerated today, 33 degrees Celsius, which is normal. Body temperature can be 33 degrees Celsius."

During the epidemic prevention and control period, whether you are entering or leaving a community, a work unit, a supermarket, or a subway or train station, your body temperature is essential. But many people have found that the body temperature measured on different occasions can vary by one to two degrees Celsius or even three degrees Celsius.

Now that Ms. Zhao wants to enter the office building of the unit, she must pass two “checkpoints” to measure temperature. The first line of defense composed of street community staff and property security is at the gate of the park. The thermometer pointed the forehead thermometer at her wrist. A few seconds later, the forehead thermometer showed a value of 35.9 degrees Celsius. The distance between Ms. Zhao's office building and the gate of the park can be described as "one step away", and the straight-line distance is only more than 10 meters. But if you want to enter the office building, you have to pass the second line of defense, and you have to measure the temperature again.

This time, the infrared thermometer was aimed at the forehead. A few seconds later, there was a beep, 36.7 degrees Celsius. "While measuring the wrist, and then measuring the forehead, which value is accurate?" Ms. Zhao found that the rules for temperature measurement seem to be different everywhere. In some places it is required to measure the forehead, in some places to measure the back of the hand, and in other places to measure the wrist, it is required to open the cuff to measure the skin of the wrist under the clothing. Ms. Zhao is a bit confused. The temperature measured by the temperature measuring gun is different, and the measuring position is also different. Why is the difference so big?

Data theory

73 new companies added in March

Contrary to the big difference in temperature measurement with temperature measuring guns, the production and sales of infrared thermometers are booming.

According to the data from the company's investigation, as of March 3, 2020, there are currently 667 companies in China engaged in infrared-thermometer- related business. In terms of quantity, Guangdong Province is far ahead with an absolute advantage of 596, accounting for 89.4% of the total number of related enterprises in the country, followed by Zhejiang, Jiangsu and Shandong. Since 2020, my country has added a total of 147 related companies operating the temperature gun business, accounting for 22% of the total, and they are still mainly concentrated in Guangdong Province. It is worth mentioning that since March, my country has added 73 related companies operating in the temperature gun business, and the growth rate is amazing.

In addition, judging from the time of establishment, most of the companies are relatively young, with 58% of companies established within 5 years, and only 68 companies established more than 10 years ago.

Since the beginning of February, market supervision departments across the country have increased their inspection and supervision of anti-epidemic products such as masks, forehead guns, and disinfectants. Among them, in the case of price violations during the epidemic prevention period announced by the General Administration of Market Supervision, a medical device company in Yuncheng, Shanxi, sold infrared forehead thermometers and infrared detectors with a purchase price of only 45 yuan and 85 yuan at high prices of 590 yuan and 800 yuan, respectively. The result was a fine of 500,000 yuan.

The reporter found that, in contrast to the popularity of forehead temperature guns, the lack of standards for forehead temperature guns. It is reported that there is currently no unified national standard for forehead guns. Since the infrared forehead thermometer is a medical device, there will be a batch number of the drug regulatory department on the body, nameplate or packaging. Industrial temperature measuring guns do not have the batch number of the drug regulatory department. Consumers can use this as a criterion when purchasing, so as to avoid buying the wrong product.

The industry also called for greater supervision and a comprehensive review of the current status of the production capacity of the forehead gun supply chain. With the passage of the most scarce stage of epidemic prevention materials, the current registration threshold should be tightened, and at the same time, the crackdown should be increased to regulate market access and promote The forehead gun industry is back on track.


Outdoor wrist measurement Indoor forehead measurement

People usually call the thermometer gun and forehead thermometer, and the professional name is "infrared forehead thermometer." As required, the temperature should be measured on the forehead. Wu Jian, director of the temperature room of the Thermal Engineering Institute of Beijing Academy of Metrology and Testing Sciences, told this reporter that a qualified forehead gun, the laboratory temperature measurement error is controlled within plus or minus 0.2 degrees Celsius to 0.3 degrees Celsius.

Since the forehead thermometer uses a non-contact temperature measurement method, the accuracy is greatly affected by the surrounding environment. If the weather is cold and the forehead thermometer is used outdoors, then there may be "inaccurate" situations . Therefore, choose different measurement locations according to different environmental conditions. When the outdoor temperature is low, the person’s forehead is directly exposed to the cold air. At this time, if the temperature is measured against the forehead, the measured body temperature will be relatively low; and the person’s wrist usually has clothing Covered, the temperature of the wrist is relatively less affected by the surrounding environment, so when the outdoor temperature is low, it will be more accurate to measure the temperature of the wrist under clothing with a forehead thermometer.

If the temperature is measured indoors and the room temperature is guaranteed, then the temperature measurement against the forehead will obtain a more accurate value.

"During the epidemic, forehead thermometers are mainly used for temperature measurement and preliminary screening, not for accurate medical diagnosis." Wu Jian explained that when the outdoor temperature is low, if the temperature is measured at the gate of the community, it may be measured by every resident. The body temperature of the resident is relatively low. As long as a few people are measured by the thermometer, the temperature of a resident is probably higher than everyone else, for example, it reaches 37 degrees Celsius. The thermometer will be vigilant and further confirm.