What is mark pass, temperature instrument of transfer can be divided into several classes?

With international temperature scale, the temperature value can be accurately at the same time in the countries all over the world get repetition. In order to ensure the production and scientific research work in the use of all kinds of thermometer table correctly, you need to international temperature scale through specific numerical metrology department, on a regular basis, step by step is passed on to the second level measuring instrument, this process is called scale transfer. If temperature instrument according to the scale of transfer can be divided into three categories. （ 1) Job reference thermometer that with modern science and technology can achieve the highest accuracy replicate our and save international temperature scale numerical thermometer is called a baseline thermometer. Used for temperature benchmark benchmark thermometer called work of dissemination of the thermometer. （ 2) Standard thermometer in the limit of precision grade, used for temperature thermometer is called the standard of dissemination of the thermometer. Our standard thermometer generally divided into two levels, namely the first-class standard thermometer and second-class thermometer. （ 3) Used in production and scientific research test work of workers and peasants of all kinds of thermometer, referred to as the work with a thermometer. Work with a thermometer in China generally divided into level 1, level 2 and level 3.