What are the installation requirements and precautions for thermal resistors

Attention should be paid to the installation of thermistor, which is conducive to accurate temperature measurement, safe and reliable, easy maintenance, and does not affect equipment operation and production operation. To meet the above requirements, the following points should be noted when selecting the installation location and insertion depth of the thermistor:
1. In order to ensure sufficient heat exchange between the measuring end of the thermistor and the measured medium, the position of the measuring point should be selected reasonably, and the installation of the thermistor near the dead corners of valves, elbows, pipelines, and equipment should be avoided as much as possible.
2. Thermistors with protective sleeves suffer from heat transfer and dissipation losses. To reduce measurement errors, thermocouples and thermistors should have sufficient insertion depth:
1) For measuring the temperature of the fluid at the center of the pipeline, the measuring end of the thermistor should generally be inserted into the center of the pipeline (vertically or obliquely installed). If the diameter of the tested fluid pipeline is 200 millimeters, the insertion depth of the thermistor should be selected as 100 millimeters;
2) For temperature measurement of high temperature, high pressure, and high-speed fluids (such as main steam temperature), in order to reduce the resistance of the protective sleeve to the fluid and prevent the protective sleeve from breaking under the action of the fluid, shallow insertion of the protective tube or the use of a hot sleeve thermistor can be adopted. The shallow insertion type thermal resistance protective sleeve should be inserted into the main steam pipeline to a depth of not less than 75mm; The standard insertion depth for hot sleeve thermal resistors is 100mm.
3) If it is necessary to measure the temperature of the flue gas inside the flue, even though the diameter of the flue is 4m, the insertion depth of the thermistor is 1m.
4) When the insertion depth of the measuring element exceeds 1m, it should be installed vertically as much as possible, or support frames and protective sleeves should be added.
Precautions for installation of thermal resistance:
1. Thermal resistors should be installed vertically on horizontal or vertical pipelines as much as possible. When installing thermal resistors, protective sleeves should be provided for easy maintenance and replacement.
2. When measuring the temperature inside the pipeline, the length of the component should be on the centerline of the pipeline (i.e. the insertion depth of the protective tube should be half the diameter of the pipe).
3. When installing the temperature dynamic coil gauge, the opening size should be appropriate and the installation should be aesthetically pleasing.
4. Use high-temperature resistant cables or high-temperature resistant compensation wires in high-temperature areas.
5. Choose different measuring components according to different temperatures. Generally, when measuring temperatures below 400 ℃, a thermistor is selected.
6. The wiring should be reasonable and beautiful, and the pointer indication should be correct.
There are many installation forms for platinum thermistors, including fixed thread installation, movable thread installation, fixed flange installation, movable flange installation, movable pipe joint installation, straight pipe joint installation, and so on.