A thermometer picture with a high fever of 39 40℃

The picture is as follows: 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. When you see the thick mercury column from the front, you can read the corresponding temperature value, and then look at the triangle between the scale and the number; The function of triangle is to enlarge. Hold the top of the thermometer with two fingers and shake it gently, and you will see a metal wire.

The neck of the mercury thermometer near the lower vacuole is a very narrow neck. When measuring body temperature, the mercury in the vacuole expands when heated, and the mercury can rise from the neck to a certain position of the pipe string. When it reaches thermal equilibrium with body temperature, the mercury column is constant.

When the thermometer leaves the human body, the external temperature is low, and when it meets cold water, the volume of silver shrinks, and it is disconnected at the narrow neck, so that part of the mercury that has risen in the tube cannot return, and it still maintains the height of the mercury column when it contacts with the human body. Thermometer is one of the highest thermometers, which can record the highest temperature measured by this thermometer.