How to Properly Use an Infrared Body Thermometer
Experts from the Chinese Academy of Metrology have provided guidance on the correct use of anti SARS infrared radiation human thermometers.
They pointed out that infrared radiation thermometers measure the temperature of the human body surface such as the forehead. The surface temperature is not only related to the human body temperature, but also affected by the blood circulation and thermal conductivity under the receptor surface, as well as the surface heat transfer conditions. In order to accurately and reliably reflect changes in human body temperature using an infrared radiation thermometer, eight points must be achieved:
--Try to require the measured person to stay in the measurement environment for a sufficient amount of time, so that the surface heat transfer conditions of the measured person are the same or similar. For example, at an airport, measurements should be taken 10 minutes after passengers arrive at the airport terminal. At this time, the ventilation and temperature conditions in the building are basically stable, and the external heat exchange conditions on the passenger's forehead are basically similar.
--The measurement location should be chosen indoors as much as possible, and avoid direct sunlight on the infrared radiation thermometer and the forehead of the person being measured.
--To accurately estimate the distance of the person being measured.
--The temperature of a person's forehead is generally 1 to 3 degrees Celsius lower than the temperature of their armpits. At this point, the criterion for a feverish armpit temperature should be switched to the forehead temperature.
--Infrared ear thermometers are used to measure ear temperature and can be completed within 1 second. As the eardrums and ear canals of humans are less affected by external environmental conditions, infrared ear thermometers can accurately measure body temperature. The human ear temperature is generally 0.4 degrees Celsius higher than the armpit temperature. At this point, the reading of the infrared ear thermometer should be converted from the criterion of axillary temperature with fever to the criterion of ear temperature.
--To ensure the accuracy and stability of infrared radiation thermometers, regular calibration comparisons should be made with standard calibration devices.
--Non contact infrared radiation thermometers are divided into industrial and medical types. When measuring body temperature, medical infrared radiation thermometers should be selected because industrial thermometers have a wide range, low resolution, and large errors.
--The various thermometers are ranked in descending order of measurement accuracy as follows: medical thermometers, infrared ear thermometers, and surface infrared radiation thermometers. From the perspective of preventing SARS, infrared ear thermometers are more accurate than surface infrared radiation thermometers.
