What is a Forehead Thermometer?

Infrared thermometer ^[1] is used to measure body temperature through infrared rays, which are divided into two types: contact type and non-contact type. Infrared thermometers are relatively safe and accurate for temperature measurement, suitable for elderly, children, hospitals and families.

Chinese name: Infrared thermometer
Foreign name: Infrared Thermometer

Management category: Class II medical devices
Category Name: thermometer

Definition of infrared thermometer

Infrared thermometer is a kind of measuring instrument that uses the principle of radiation to measure human body temperature. It uses an infrared sensor that only absorbs the infrared radiation emitted by the human body without emitting any rays to the outside world, and senses the human body temperature through a non-contact method ^[2] .

How infrared thermometers work

The human body's infrared thermal radiation is focused on the detector, and the detector converts the radiated power into an electrical signal, which can be displayed in temperature units after being compensated for the ambient temperature.

Infrared thermometer related data

Normal body temperature range at different measurement locations

Measurement site	Normal temperature	Normal temperature
anus	36.6 ~ 38	97.8 ~ 100.4
Oral cavity	35.5 ~ 37.5	95.9 ~ 99.5
Underarm	34.7 ~ 37.3	94.4 ~ 99.1
ear	35.8 ~ 38	94.6 ~ 100.4

Normal body temperature range at different ages

age	Normal temperature	Normal temperature
0 ~ 2 years	36.4 ~ 38	97.5 ~ 100.4
3 to 10 years old	36.1 ~ 37.8	97.0 ~ 100.0
11 ~ 65 years old	35.9 ~ 37.6	96.6 ~ 99.7
> 65 years	35.8 ~ 37.5	96.4 ~ 99.5

Basic structure of infrared thermometer

Contact infrared thermometer. Taking an ear thermometer as an example, it mainly consists of a housing, a temperature probe, a temperature sensor, a PCB circuit, a liquid crystal display, a buzzer, and a battery.
Non-contact infrared thermometer. Taking the forehead gun as an example, it mainly consists of an infrared probe component, a main circuit board component, an LCD display component and a housing component.

Infrared thermometer classification

Infrared thermometers are mainly divided into contact infrared thermometers and non-contact infrared thermometers.

Contact infrared thermometer. Common ear thermometers, forehead thermometers, and multifunctional thermometers can take accurate temperature from the ear in one second. When using, gently straighten the ear canal, insert the temperature measuring head into the ear canal, and press the upper end of the temperature measurement for one second. Then you can read the accurate body temperature from the LCD screen with at least one decimal place, which is safe and secure When replacing the protective rubber sleeve during use, it can avoid bacterial infection, and it is safe even if it is shared by the whole family.

Temperature measurement diagram

2. Non-contact infrared thermometer. The most common is a forehead gun, which can be used to measure the temperature of the human body. Just point the probe at the forehead and press the measurement button to get the measurement data in just a few seconds. It is very suitable for patients with severe illness, the elderly, infants and young children. However, in the early stage of use, the user may not be familiar with this operation method, and may obtain several different measurement data. Generally speaking, the measured maximum value is the required data. The user will be more satisfied with this thermometer after being familiar with it.

How to use infrared thermometer

Contact infrared thermometer. Take ear thermometer as an example:
1) Power on
2) Gently pull the auricle to straighten the ear canal, fix the head, insert the sensor into the ear hole and align the eardrum to start the temperature measurement. Note that when measuring, the ear thermometer sensor should be inserted into the ear hole facing the eardrum. If the eardrum is not aligned, the measured temperature will be lower than the actual body temperature.
3) The ear temperature is displayed on the screen, the value is recorded, and the temperature measurement is over.

How to use the ear thermometer

2. Non-contact infrared thermometer. Take the forehead gun as an example:

1) Power on

2) Point the infrared detector part to the center of the foreheadabove the center of the eyebrow and keep it vertical. The measurement area must not be covered by hair. If there is sweat, it should be wiped dry. The distance from the forehead is about 3-5cm.

3) The body temperature is displayed on the screen, the value is recorded, and the temperature measurement is completed.

Advantages and disadvantages of infrared thermometers

The infrared thermometer has the advantages of convenient, simple, fast and accurate temperature collection, which is very suitable for patients with severe illness, the elderly, infants and young children. The disadvantage is that it is susceptible to ambient temperature, and the error is large in this case ^[3] .

Precautions for using infrared thermometer

Do not use the ear thermometer if you have ear diseases such as external otitis or otitis media.
Do not use an ear thermometer when your ears are wet after swimming or bathing.
When the person to be measured comes from a place with a large difference in temperature from the ambient temperature, they should stay in the measuring environment for at least 5 minutes, and measure after the temperature is consistent with the ambient temperature.
Fever patients with perspiration, cold compresses, and other cooling measures will lower the measurement results, and temperature measurement should be avoided in this case.
It cannot be measured in places with large air flow such as fans, air conditioners.
Do not use in direct sunlight.
It is recommended to measure about 3 times during the measurement, and the interval between each measurement is 3-5 seconds, whichever is the most displayed data.

Infrared thermometer daily care

Dirt on the outside: Wipe the dirt with a clean, soft cloth and water, or wipe with a cotton swab and medical alcohol. Wiping with medical alcohol can also have the effect of disinfection. Take care not to add too much water or alcohol to prevent damage to the product if it flows into the interior.
Internal dirt: The internal infrared detector is an important device. Do not touch or press with your fingers or other objects, otherwise the accuracy of the measurement value will be affected. When the infrared detector is found to be dirty, wipe it with a cotton swab moistened with 95% absolute alcohol.