Are infrared thermometers dangerous?
At the press conference held by the State Council on the Joint Prevention and Control Mechanism of Novel Coronavirus Infection and Pneumonia, Feng Luzhao, a researcher at the China Centers for Disease Control and Prevention, responded to the question whether infrared thermometers are harmful to the human body. The working principle of infrared thermometers is to The infrared thermal radiation of the human body is focused on the detector, and the detector converts the radiation power into an electrical signal, and the electrical signal is displayed in units of temperature after being compensated for the ambient temperature.
"So, the infrared thermometer does not emit infrared rays to the human body, but receives the infrared heat radiation emitted by the human body, so there is no harm to the eyes and body." Feng Zhaolu said.
Qi Haiyan, deputy chief physician of the Department of Ophthalmology at Shunyi Women and Children's Hospital of Beijing Children's Hospital, said that if the intensity of infrared rays is high, it will irritate and damage the eyes, and in severe cases, it can cause cataracts, retinal damage, and even blindness. The eyes have a certain absorption effect on infrared rays with a wavelength of less than 1.5 microns. If the eyes are directly irradiated, the liquid in the eyeball will react due to the absorption of short-wave infrared rays, causing eye diseases. "However, infrared thermometers on the market do not emit infrared rays. The red light emitted is for convenient positioning. Its working principle is to measure by receiving infrared wavelengths from the heat emitted by the human body. Qi Haiyan further explained that the human body is at 36°C- The infrared wavelength emitted at 37°C is 9-13 microns, which is the self-radiation wavelength of the organism. The higher the temperature of the object, the shorter the emitted wavelength. For example: when the temperature of the object reaches 300°C, the emitted infrared wavelength is 6.8 microns , and the highest human body temperature is a little over 40°C. At this time, the emitted infrared wavelength is greater than 6.8 microns, which is much higher than the wavelength range that the eyes can absorb (1.5 microns), so it is safe for the human body to emit far infrared rays. Infrared measurement Thermometers are divided into two types: contact and non-contact. Since the main route of transmission of new coronary pneumonia is through respiratory droplets and close contact, the current use is non-contact to avoid the infection of new coronary pneumonia due to contact. Non-contact infrared The thermometer will measure different parts, such as the forehead, neck, wrist, etc. Using an infrared thermometer to measure the neck will not have any effect on the thyroid gland. Qi Haiyan believes, "Measuring the wrist is the most convenient and fast. Please cooperate during the epidemic. Measure body temperature, use infrared electronic thermometer with confidence. "
Does the infrared thermometer have radiation?
The principle of the infrared thermometer is that the heat of the human body will be dissipated into the environment in the form of thermal radiation. The human infrared thermometer detects the thermal radiation of the human body through the built-in sensor, so as to achieve the purpose of measuring body temperature. The infrared thermal imaging body temperature rapid screening instrument uses infrared temperature measurement technology to quickly measure the surface temperature of the human body in a non-contact manner, and it is an instrument that warns when the measured temperature reaches or exceeds the preset warning temperature value.
So basically the human body infrared thermometer itself will not have much radiation.
