Water thermometer, thermometer is usually 1 ℃, while the thermometer is 0.1 ℃.
Range: thermometers generally range from -20 ° C to 110 ° C, thermometers range is 35 ° C to 42 ° C.
Minimum scale value: the minimum scale value of the thermometer is 1 ℃, the minimum scale value of the thermometer is 0.1 ℃.
Operation: thermometers can not leave the measured object readings, thermometers can leave the human body readings. The thermometer should be thrown downward a few times with force before use, while other ordinary thermometers can not be thrown before use.
The working substance of the thermometer is mercury. The volume of its glass bubble is much larger than that of the thin tube above it. The mercury in the bubble produces small changes due to the influence of body temperature, and the expansion of the volume of mercury causes a significant change in the length of the mercury column in the tube.
Expanded information:
The human body temperature varies between 35°C and 42°C, so a thermometer has a scale of 35°C to 42°C, and the range of each degree is divided into 10 parts, so the thermometer can be accurate to 1/10th of a degree. To take a reading, take it out of your armpit or mouth, when the temperature of the glass bubble underneath it decreases.
In order for his readings to still be representative of body temperature, a special design had to be made, which is a very thin thin tube between the glass bulb and the straight glass tube - the indentation. The lower part of the thermometer near the liquid bubble at the neck of the tube is a very narrow curved neck, measuring body temperature, the mercury in the glass bubble with the increase in temperature, the expansion occurs, through the thin tube squeezed to the straight tube, by the neck part of the rise to a certain position in the tube, when and the temperature of the body to reach a thermal equilibrium, the mercury column constant.
The outside world temperature is low, the mercury is cold volume contraction, in the narrow part of the curved neck disconnect, so that the mercury in the tube can not be returned to the glass bubble, still maintains the height of the mercury column in contact with the human body to achieve, so it is out of the body is still the temperature of the human body.
After using the thermometer should be "back to the table", that is, holding the thermometer's upper part of the force down to shake, can make has risen into the tube of mercury, back to the glass bubble. Other thermometers can not shake, this is the thermometer and other liquid thermometer of a major difference.
Baidu Encyclopedia - Mercury Thermometer
Baidu Encyclopedia - Body Thermometer