Thermocouple was used to measure the temperature of a measuring instrument, some thermocouple calibration is an international scale, in order to make it easy to use for everyone, everyone is necessary to learn about the international scale, can accurate readings, here to give you introduce thermocouple international temperature scale. Temperature units: thermodynamic temperature is the basic physical quantities hand, kelvin, its unit is defined as 1/273 of the triple point of water thermodynamic temperature. 16, used in 273. 15 k ( Freezing point) A difference of temperature, so this method is retained. According to the definition, c is equal to the size of the kelvin, temperature difference can be expressed in degrees Celsius or kelvin. International scale ITS - Define both international degrees kelvin (90 Symbol T90) And the Celsius temperature ( Symbol t90) 。 International scale ITS - 90 the general principles of: ITS - 90 by 0. 65 k up to Max Planck radiation law using monochromatic radiation actual high temperature can be measured. 它的, 90 set so that the full range, any better estimate when adopted at temperature T, compared with the direct measurement of thermodynamic temperature T90 measurement more convenient, and more precise, and has a high reproducibility. 它的, Temperature range of 90: the definition of 0. 65 k to 5. 00 between k, he T90 he from 3 and 4 of the relation between the steam pressure and temperature. Temperature zone is 3. To the neon triple point (0 k 24. 5661 k) Between T90 is helium gas thermometer to define. The third zones for flat Heng hydrogen triple point ( 13. 8033 k) To the freezing point of silver ( 961. 78℃） Between, T90 is defined by platinum resistance thermometer, it USES interpolation method for dividing the definition of a set of rules. Silver freezing point ( 961. 78℃） Temperature range of the above, T90 is defined by the Planck radiation law emersion instruments for optical pyrometer.