Installation location and insertion depth of integrated explosion-proof thermistor

Installation location and insertion depth of integrated explosion-proof thermistor
The integrated explosion-proof thermistor utilizes the principle of gap explosion-proof to design junction boxes and other components with sufficient strength. All components that can generate sparks, arcs, and dangerous temperatures are sealed inside the junction box cavity. When an explosion occurs inside the cavity, it can be extinguished and cooled through the gap between the joint surfaces, preventing the flame and temperature after the explosion from being transmitted outside the cavity, thus enabling temperature measurement.
When selecting the installation location and insertion depth of the integrated explosion-proof thermistor, attention should be paid to:
1. Explosion proof thermal resistors with protective sleeves have heat transfer and heat dissipation losses. In order to reduce measurement errors, thermocouples and thermal resistors should have sufficient insertion depth:
(1) For explosion-proof thermal resistors used to measure the fluid temperature at the center of pipelines, their measuring end 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, although the diameter of the flue is 4m, the insertion depth of the thermistor is 1m;
(4) When the insertion depth of the measuring component exceeds 1m, it should be installed vertically or equipped with support frames and protective sleeves as much as possible.
2. In order to ensure sufficient heat exchange between the measuring end of the integrated explosion-proof thermistor and the measured medium, the location 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.
Integrated explosion-proof thermistor is a primary component that converts temperature changes into resistance value changes, usually requiring the resistance signal to be transmitted to a computer control device or other primary instruments through leads. Industrial thermal resistors are installed on the production site and there is a certain distance between them and the control room, so the leads of the thermal resistors will have a significant impact on the measurement results.