The popular science!Take you to learn about the human infrared thermometer

2021/01/05

During the epidemic prevention and control period, human infrared temperature measuring equipment has been widely used in hospitals, airports, stations, farmers' shops, supermarkets, residential communities and other public places due to its non-contact, high efficiency, easy to use and other characteristics. However, how to correctly use the temperature measuring equipment and what precautions should be noted during the use.

Briefly, there are two main types: contact and non-contact thermometers. The difference between the two is whether there is contact with the skin.Contact thermometers mainly include glass liquid thermometers, medical electronic thermometers, etc.Non-contact thermometers mainly include red ear thermometers, infrared frontal thermometers, infrared temperature screening instruments, etc.In terms of measuring accuracy, contact thermometers are higher than non-contact thermometers.Infrared frontal thermometer and infrared screening instrument are the most widely used in the epidemic prevention and control work.In particular, the surveyor should read the instruction carefully before use.

What are the technical indexes and applications of all kinds of human infrared thermometers?

Instrument and equipment name maximum allowable error temperature measurement time application site

Red outer ear thermometer ±0.2℃ 5S-10s home and clinic

Infrared frontal thermometer ±0.3℃ 3s-5S office, unit, plant area

Infrared temperature screening instrument ±0.4℃ real-time display airport, station, subway

(1) The measured data are only used for preliminary screening of abnormal human temperature, and cannot be used as medical diagnostic data;

(2) Industrial infrared thermal imagers, with low measurement accuracy and generally maximum allowable error of ±1℃, are not recommended for epidemic prevention and control.

What are the precautions?

Red ear thermometer

1. Check whether the ear canal is clean before use, because earwax may affect the accuracy of infrared measurement;

2. After each person is tested, the probe should be cleaned with alcohol cotton to prevent cross infection.

Infrared frontal thermometer

1. Before use, it shall be set correctly according to the requirements of the manual and be switched to the temperature mode (some thermographs turn on and default to the temperature mode);

2. Keep the thermometer upright, and the distance between the detection head and the forehead is generally (3-5)cm. The measuring position is the center of the human forehead and above the eyebrow.

Why is the temperature value of infrared frontal thermometer inaccurate?

The ambient temperature of infrared frontal thermometer is 16℃ ~ 35℃.In winter, when the temperature is low, most of the monitoring sites for epidemic prevention and control are outdoors, and the equipment used outdoors for a long time is prone to deviation.

In the cold environment for a long time, the forehead temperature will be low.

Improper measurement methods can also result in inaccurate temperature measurement values, such as close to the forehead, etc.

How to measure body temperature under low temperature environment?

In view of the fact that most of the monitoring sites for epidemic prevention and control are located outside with low ambient temperature, firstly, the infrared frontal thermometer should be prevented from being exposed for a long time, generally no more than 1 minute.Second, if there is a large measurement error or abnormal body temperature, the glass thermometer should be used in time to remeasure the body temperature;Thirdly, the infrared frontal thermometer should be checked at least once every 3 ~ 5 hours.

The infrared frontal thermometer should be placed in the greenhouse for more than 5 minutes to make its own temperature consistent with the ambient temperature. The measured person should stay in the greenhouse for at least 3 ~ 5 minutes before the measurement.

Generally, three repeated measurements can be made to take the average value as the temperature measurement result.

How to verify the accuracy of infrared frontal thermometer temporarily in use?

In the application of infrared frontal thermometer in screening, the accuracy verification can be carried out in time by referring to the following verification methods after the environmental temperature and other conditions change significantly.

Accuracy verification method

(1) Take the reliable contact thermometer as the reference standard;

(2) A comparison group of normal body temperature controls was selected, and the comparison group was determined according to the selection method of normal body temperature controls;

(3) the contact thermometer standard and infrared forehead thermometers (patterns) temperature measuring body temperature normal comparison group, at the same time in infrared forehead temperature average temperature measurement and non-contact thermometer temperature average value as the difference between the temperature measurement error, i.e., the temperature error = average infrared forehead thermometer temperature - contact thermometer temperature averages;

(4) If the temperature error is within ±0.5℃, the infrared temperature statistical estimate is accurate;

(5) If the temperature error exceeds ±0.5℃, it is recommended to stop using.