1. The installation position of the temperature instrument should be selected in a place where the temperature of the medium is sensitive and representative, and should not be selected near the resistance parts such as valves and welds and where the medium stream is at a dead angle. The local indication thermometer should be installed in a place where it is easy to observe. The thermocouple should be installed away from magnetic fields. If the temperature primary component is installed at the corner of the pipeline or inclined installation, it should be reversed to the flow direction. When bimetal thermometer is installed in ≤DN50 pipeline or thermal resistance, thermocouple is installed in ≤DN70 pipeline, expansion pipe should be added. The enlarged tube should be made according to standard drawings (see Chapter 10). The temperature envelope of the pressure thermometer must be fully immersed in the measured medium.

       2. The secondary temperature meter should be used together. The thermal resistance and thermocouple should be equipped with corresponding secondary meters or transmitters. Pay special attention to the index number, tables with different index numbers cannot be misused.

       3. The thermocouple must use the compensating wire of corresponding index number. The thermal resistance should adopt the three-wire connection method to offset the influence of the ambient temperature. Each secondary meter has its own external line resistance requirements. In addition to compensating for the line resistance of the wire or cable, manganese copper wire must be used to match the corresponding resistance to meet the requirements of the secondary meter.

       4. The compensation wire or cable is connected to the thermocouple or thermal resistance through a metal flexible tube.

       5. If there is a pressure point or a temperature point on the same pipeline at the same time, the pressure point should be at the temperature.

       6. The temperature secondary instrument installation is relatively simple. Install the secondary meters that have passed the single calibration and install them on the designated instrument panel or frame according to the installation instructions. The temperature secondary instrument is a type of display instrument that has developed rapidly in recent years. Most of the secondary meters indicated by pointers (that is, moving coil indicators) are gradually replaced by digital display thermometers with completely consistent dimensions.