The novel coronavirus epidemic situation in the spring of 2020 made masks, alcohols, disinfectants and thermometers become various products. We also formed some new habits in our daily life, such as wearing masks, hand disinfection and measuring body temperature every day. There are also temporary posts at the entrances of major public places, where the temperature of each person entering is measured by a specially assigned person, and only when the temperature is normal can they enter. At present, the common thermometers on the market are forehead thermometer, ear thermometer and mercury thermometer. Which one is better? Let me give you a detailed analysis.

Understand the significance of temperature measurement

Human body temperature is one of the important vital signs reflecting the physiological state of the body. Body temperature is affected by nerve center regulation and diseases, so it is important to measure body temperature for diagnosing diseases. According to whether the temperature measurement device is in direct contact with the human body, the temperature measurement methods are divided into contact temperature measurement and non-contact temperature measurement. Forehead thermometer and ear thermometer are non-contact thermometers, while mercury thermometer is contact thermometers.

Working principle and using method of three kinds of thermometers

1.Working Principle

1)Forehead Thermometer

When the temperature of any object is higher than absolute zero (- 273 "C), it will send out infrared rays. The forehead temperature gun receives the infrared rays from the forehead through the sensor to get the temperature sensing data.

2)Ear Temperature Gun

The lower colliculus is the center of human body temperature, and the tympanic membrane temperature is proportional to the change of the lower colliculus temperature. The ear temperature gun indirectly obtains the lower colliculus temperature by scanning the thermal energy released by the membrane and surrounding tissues through infrared ray, so as to obtain the human body temperature.

3)Mercury Thermometer

Based on the principle of mercury volume expansion and contraction, the length of mercury column in glass tube is changed obviously to read.

2.Usage Method

1.Advantage

1)Forehead Thermometer

① The measurement time is short.
② No direct contact with human body, reduce pollution.
③ LCD display, easy to read.

2)Ear Temperature Gun

The same as forehead thermometer

3)Mercury Thermometer

① Low price.
② Stable performance and small error.

2.Usage Method

1)Forehead Thermometer

Put the forehead temperature gun in the middle of the forehead and measure it at a distance of 5-6cm from the infrared ray.

2)Ear Temperature Gun

Before use, replace it with a new earmuff, and fix the auricle back and up, so that the ear canal is straight. Put the ear temperature gun probe into the ear canal for measurement.

3)Mercury Thermometer

Throw the mercury thermometer below 35 ℃ before use, and put it down in the armpit, cover the mercury head completely and read the data after sitting for 5 minutes.

Usage Method

Clinical data show that the temperature difference of the forehead, ear and armpit has clinical significance. It can be considered that axillary temperature > ear temperature > frontal temperature

When the body temperature is normal, there is no significant difference among the three kinds of thermometers. Forehead thermometer or ear temperature gun can be used to replace the traditional mercury thermometers to improve the working efficiency. However, in the case of fever, there are significant differences in the values measured by the three thermometers. The traditional mercury thermometer is the "gold standard" for temperature measurement, so forehead thermometer or ear thermometer can not be used to replace the traditional mercury thermometer to avoid excessive error [3]. Therefore, the mercury thermometer is suitable for the temperature monitoring of the fever population. Ear temperature gun can reflect human body temperature more accurately than forehead thermometer, and the temperature measurement is fast, which is suitable for infants and young children who are easy to move and do not cooperate with temperature measurement. The frontal temperature gun is easy to operate and does not need human contact, so it is suitable for temperature screening of a large number of people.

To sum up, there is no better thermometer, please select the most suitable one according to the actual situation