On what principle is a thermometer made?

A thermometer is an instrument for measuring body temperature. In the past, people often used mercury thermometers to measure, but mercury thermometers are more troublesome to use and do great harm to human body. Nowadays, many people are using electronic thermometers, which can measure the temperature quickly, simply and with little harm. On what principle is the thermometer made?

On what principle is a thermometer made of mercury? Thermometers are made according to the principle that mercury expands with heat and contracts with cold. The structure of thermometer is very special. There is a thin contraction where the glass bulb meets the tubule. When the thermometer leaves the human body, the mercury cools and contracts, and the mercury column is disconnected at the neck, so the mercury on it cannot return, so the thermometer can continue to display the human body temperature after leaving the human body.

The electronic thermometer uses the electrical signal output by the temperature sensor to directly output a digital signal, or converts the current signal (analog signal) into a digital signal that can be recognized by the internal integrated circuit, and then displays the temperature in digital form through the display (such as liquid crystal, digital tube, LED matrix, etc.). ), you can record and read the highest value of the measured temperature.

How to Use Mercury Thermometers Thermometers usually measure body temperature by measuring armpits, mouth and rectum. Among them, underarm measurement is the most common method:

1. If the mercury thermometer is not used alone, wipe it with alcohol cotton before measurement and dry it;

2. Drop the mercury in the traditional mercury thermometer below 35 degrees;

3. The mercury thermometer should be clamped under the armpit, and the mercury should be in the middle of the armpit;

4. Don't loosen your arm or walk when clamping;

5. Take out the mercury thermometer after measurement, and then clean it.

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.