The selection of temperature measuring instruments is an important task. If not selected properly, it will not only fail to meet the production requirements, but may also cause production accidents and cause undue losses. The selection of measuring instruments should consider the following aspects:

       First,choose the type of temperature measuring instrument according to the process requirements

       The choice of instrument type is an important prerequisite for ensuring the normal operation of the instrument and safe production. Therefore, before selecting the instrument, you must deeply understand the mastering process and the requirements imposed by the process on the instrument. Generally, you should understand the following process conditions:

       1. The temperature change range and speed of the measured object;

       2. The physical and chemical properties of the tested object, such as corrosive, oxidizing or reducing atmosphere, viscosity, dirtiness, whether it is flammable, explosive, toxic, etc.;

       3. Whether the measured object is stationary or moving, is it gaseous, liquid temperature or solid temperature, is it the measuring point temperature or the average temperature;

       4. Whether the signal needs to be remotely transmitted, automatically recorded, and alarmed;

       5. Environmental conditions at the installation site of the instrument, such as temperature, humidity, electromagnetic field, vibration, etc.

       Second, the choice of temperature measurement instrument accuracy grade

       The accuracy grade of the instrument is determined according to the measurement error allowed in the production process.

       Selection of temperature measuring instrument range

       When measuring temperature, the accuracy of the measurement is not only related to the accuracy level of the selected instrument, but also related to the range of the instrument. In other words, instruments with the same accuracy level but different ranges may have different errors. Therefore, when selecting the range of the instrument, the instrument with the same accuracy level should try to select the instrument with the upper measurement limit close to the measured temperature, that is, when the instrument is running, try to make it work at the upper measurement limit. However, in order to ensure the safety of the instrument, some room should be left, and the measurement range of normal use is generally 30 to 90% of the full range.