1, alcohol thermometer
Alcohol thermometer, is the use of alcohol thermal expansion and contraction of the nature of the thermometer. In 1 standard atmospheric pressure, alcohol thermometer can measure the highest temperature is generally 78 ℃. Because alcohol at 1 standard atmospheric pressure, its boiling point is 78 ℃. But the pressure inside the thermometer is generally higher than 1 standard atmospheric pressure, so there are some alcohol thermometers with ranges greater than 78 degrees.
2, mercury thermometer
Mercury thermometer, is a kind of expansion thermometer, the freezing point of mercury is -39 ° C, boiling point is 356.7 ° C, measuring the temperature range is -39 ° C - 357 ° C, it can only be used as a local supervision of the instrument. Using it to measure temperature is not only simple and intuitive, but also avoids the errors of external remote thermometers.
3, gas thermometer
Gas thermometer is a use of a certain mass of gas as a working substance thermometer. Gas thermometer to reflect the ideal gas temperature scale for the standard temperature scale. The temperature measured with the gas thermometer and thermodynamic temperature coincide. Gas thermometer is in the container with hydrogen or nitrogen (more hydrogen or helium as a temperature measurement material, because hydrogen and helium liquefaction temperature is very low, close to absolute zero, so it is a wide range of temperature measurement, this thermometer is very high accuracy, mostly used for precision measurements).
4, resistance thermometer
Resistance thermometers, also known as resistance temperature detectors (RTDs), is a use of known resistance with temperature change characteristics of the material made of temperature sensors. Because they are almost invariably made of platinum, they are often called platinum resistance thermometers. They are slowly replacing thermocouples in many industrial applications below 600C.
The most commonly used resistance thermometers all use a temperature sensing element made of a wire winding, mainly platinum and copper resistance thermometers, and at low temperatures carbon, germanium and rhodium-iron resistance thermometers.
5, the temperature difference thermocouple thermometer
The use of temperature difference thermocouple to measure the temperature of the thermometer. Will be two different metal conductor ends were connected to form a closed loop, one end of the heating, the other end of the cooling, then the two contact points due to the temperature difference between the electric potential will be generated, the conductor in the current will occur. Because this temperature difference electric potential is a function of the temperature difference between the two contact points, so the use of this feature made of thermometers.
Baidu Encyclopedia-Temperature Monitor