Mercury thermometer, a kind of thermometer, is made of glass and contains 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.
Mercury thermometer contains about 65438 0 grams of mercury. After being smashed, all the leaked mercury evaporates, which can make the air mercury concentration in a room with a height of15m2 reach 22. 2 mg/m3. China stipulates that the maximum allowable concentration of mercury in indoor air is 0 .0 1 mg/m3. It is generally believed that when the mercury concentration is 1.2-8.5 mg/m3, people will suffer from mercury poisoning soon.
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 inhaled, mercury vapor 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 the water body, which is particularly harmful to the developing fetus and baby. In addition, with the rise of the food chain, methylmercury will be enriched in animals and humans, thus threatening global human health.
Extended data:
The basic thermometer is used to measure the basic temperature of the human body just after waking up in the morning. Compared with daily body temperature, basal body temperature is less affected by environmental factors, such as exercise or diet. This is helpful to detect the subtle changes of daily 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 under the armpit) and hold the thermometer with the upper arm to avoid dislocation or falling; Measure for 5- 10 minutes; Take out the thermometer, and after reading the temperature data, wipe the thermometer with toilet paper for next use or other people's use.
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 to read the corresponding temperature value when you see the thick mercury column from the front. When reading, be careful not to touch the mercury end of the thermometer with your hands, which will affect the mercury column and cause inaccurate measurement.
Precautions:
1. If you have sweat under your arm, dry it and measure it again.
2. If the underarm is released before the measurement time, it needs to be re-measured and the time should be recalculated.
3. Before measuring the body temperature, all the factors that affect the actual body temperature (such as drinking boiled water or cold drinks). ) should be avoided. Drinking hot drinks, strenuous exercise, emotional excitement and bathing need to wait for 30 minutes before measuring.
4. The maximum temperature of the glass thermometer is 42℃, so the temperature cannot exceed 42℃ during storage or cleaning. The thermometer cannot be put into hot water for cleaning or used to measure the temperature of water and other objects.
Caution: Glass thermometers are easily broken and may be contaminated by mercury.
References:
Baidu encyclopedia-mercury thermometer