There are six kind of thermometers in the market, three of which are infrared thermometers, which are also one of the most common ways to measure body temperature in medicine and industry.

1, mercury thermometers: primitive thermometers are still used in many families and even hospitals. The accuracy is high, but with the progress of science, people's awareness of health, understanding the harm of mercury, and gradually use electronic thermometer to replace the traditional mercury thermometer.The reason is that, the mercury thermometer glass is fragile and easy to get hurt if broken. The ordinary families do not have the correct way to deal with mercury and will be poisoned by mercury vapor.

2, electronic thermometer (thermistor type): widely used, it can measure the temperature of armpit, mouth and anus with high accuracy, and also used for temperature parameter transfer of medical detection equipment.

3, forehead temperature gun (infrared thermometer): measuring forehead surface temperature, divided into touch and non touch; according to the use of classification, also divided into human body temperature and industrial temperature. Refer to GB t 21417.1-2008 medical infrared thermometer

4, the ear temperature gun (infrared thermometer): easy to use, fast temperature measurement, but the technical requirements of the operator is higher. The maximum allowance of the ear thermometer itself is usually ± 0.2 ℃ in the range of 36-39 ℃, and ± 0.3 ℃ when it is higher than 39 ℃ and lower than 36 ℃. When used, incorrect use will also bring additional errors. If a large amount of wax in the ear canal, it will bring errors. When measuring, because the ear thermometer plugs the ear hole, the temperature field in the ear hole will change, and the indication will change if the measuring time is too long. If the measurement interval is not appropriate, the readings will be different each time.

5, the temporal artery thermometer (infrared thermometer): measuring the temperature of the temporal artery on the side of the brain hilum, just like the forehead temperature gun, requires careful resolution. It is easy to use and has high accuracy. Few domestic enterprises can produce this kind of products. It is a complex of infrared temperature measurement technology.

6, intelligent thermometer (sticker, watch or bracelet): most of these products on the market choose the patch or wearable type, which is pasted on the armpit and worn on the hand, and can be bound with a mobile phone app to monitor the temperature curve in real time. This kind of products are relatively new, there is no corresponding standard, and there is little information about the accuracy, which needs to be tested by the market.