The mercury column is very thin. The thermometer has a cylindrical magnifying glass for magnifying the mercury column. From this magnifying glass, you can see it by choosing an angle.
mercury thermometer, a kind of thermometer, is made of glass and contains a mercury column that rises with body temperature. Mercury thermometers are widely used in the medical field and ordinary families, and some pharmacies can buy mercury thermometers.
a mercury thermometer contains about 1g of mercury. After being smashed, all the leaked mercury evaporates, which can make the air mercury concentration in a room of 15m2 and 3m high reach 22. 2mg/m3. China stipulates that the maximum allowable concentration of mercury in indoor air is . 1mg/m3. It is generally believed that people will cause mercury poisoning quickly when the mercury concentration is 1.2-8.5 mg/m3.
As a heavy metal, mercury is highly toxic. Feng Xinbin, deputy director of the State Key Laboratory of Environmental Geochemistry, Institute of Geochemistry, Chinese Academy of Sciences, said that once mercury vapor is inhaled, it will enter various organs and tissues of the human body through blood circulation, and it can also damage the central nervous system through the blood-brain barrier.
Mercury is converted into methylmercury after entering water, which is especially harmful to developing fetuses and babies. In addition, methylmercury will be enriched in animals and humans with the rise of the food chain, thus threatening human health around the world.
Extended information:
The basic thermometer is used to measure the basic body temperature when the human body just wakes up in the morning. Compared with daily body temperature, basal body temperature is less affected by environmental factors, such as exercise or eating. This is beneficial to detect the daily subtle changes in body temperature. Such as ovulation or changes in thyroid function.
Before use, throw the mercury column of the thermometer below 35℃. Put the mercury end of the thermometer at the top of the armpit (that is, deep in the armpit), and clamp the thermometer with the upper arm to avoid dislocation or falling; Measure for 5-1 minutes; Take out the thermometer, and after reading the temperature data, wipe the thermometer with toilet paper so that it can be used next time or by others.
reading method: hold the tail of the thermometer with one hand, that is, the end far away from the mercury column, so that the eyes are at the same level with the thermometer, and then slowly turn the thermometer, and you can read the corresponding temperature value when you see the thick mercury column from the front. Be careful not to touch the mercury end of the thermometer with your hand when reading, which will affect the mercury column and cause inaccurate measurement.
Precautions:
1. If there is sweat under your armpit, dry it before measuring it.
2. If the underarm is released before the measurement time, it needs to be measured again and the time should be recalculated.
3. Before measuring the body temperature, all factors that affect the actual body temperature (such as drinking boiled water or cold drinks, etc.) should be avoided. Drinking hot drinks, strenuous exercise, emotional excitement and bathing should wait for 3 minutes before measuring.
4. The maximum temperature of the glass thermometer is 42℃, so the temperature should not exceed 42℃ during storage or cleaning. The thermometer should not be put into hot water for cleaning or used to measure the temperature of water and other objects.
special note: the glass thermometer is easily broken, and there is the possibility of mercury (mercury) pollution.
Reference: Baidu Encyclopedia-Mercury Thermometer