WRN-640A. Explosion-proof Thermocouple Shanghai Automation Instrument Third Factory

1、 Instrument Overview:

Flameproof thermocoupleIt is a temperature sensor widely used in chemical industry automation systems. Through temperature sensors, the temperature parameters of the controlled object can be converted into electrical signals, transmitted to display, record, and adjust instruments, and the system can be detected, adjusted, and controlled. In chemical plants, the production site is often accompanied by various flammable, explosive and other chemical gases and vapors. If ordinary thermocouples are used, it is very unsafe and can easily cause environmental gas explosions. Therefore, in these situations, explosion-proof thermocouples must be used as temperature sensors. Our company's explosion-proof thermocouple products are suitable for places with explosive gas hazards within the temperature range.

2、 Measurement principle:

Flameproof typethermocoupleIt utilizes the principle of gap explosion isolation to design components such as junction boxes with sufficient strength, sealing all components that can generate sparks, arcs, and dangerous temperatures in the junction box cavity. When an explosion occurs in the cavity, it can be extinguished and cooled through the gap of the joint surface, so that the flame and temperature after the explosion cannot be transmitted outside the cavity, thus achieving explosion isolation.

3、 Applicable occasions:

Thermocouple applications are usually used in conjunction with display instruments, recording instruments, electronic computers, etc. Directly measure the surface temperature of liquid, steam, and gas media, as well as solids, within the range of 0 ℃ to 1300 ℃, where hydrocarbons and other substances exist on the production site.

4、 Performance characteristics:

1. Multiple explosion-proof forms with good explosion-proof performance;

2. Spring loaded temperature sensing element with good seismic performance;

3. Large measurement range;

4. High mechanical strength and good pressure resistance.

5、 Technical indicators:

Product Execution Standards

IEC584

IEC1515

GB/T16839-1997

JB/T5582-91

6、 Installation method:

1. Firstly, the size of the thermocouple flange or threaded thread should be measured, and the flange or threaded base should be machined and matched.

2. Drill holes on the pipes that need to be measured based on the size of the flange or threaded base.

3. Welding of flange or threaded base: Insert the flange or threaded base into the already opened hole, and weld the flange or threaded base with the measured pipeline.

4. Tighten the thermocouple with bolts or thread it into the welded threaded base.

5. Connect the junction box of the thermocouple according to the wiring diagram and connect it to the corresponding display instrument on the dial. Note that the junction box should not come into contact with the wall of the measured medium pipeline, ensuring that the temperature inside the junction box does not exceed the range of 100 ℃. The outlet hole of the junction box should prevent short circuits in the wiring terminals due to poor sealing, water vapor, dust, and other deposits.

7、 Measurement range and basic error limit:

Note: t represents the measured temperature value (℃) of the temperature sensing element, and the thermal inertia level

Thermocouple nominal pressure: generally refers to the static external pressure that the protective tube can withstand and rupture at working temperature.

The small insertion depth of the thermocouple should not be less than 8-10 times the outer diameter of its protective sleeve (except for special products)

Insulation resistance: When the ambient air temperature is 15-35 ℃ and the relative humidity is less than 80%, the insulation resistance is ≥ 5 megaohms (voltage 100V). Thermocouples with splash proof junction boxes have an insulation resistance of ≥ 0.5 megaohms (voltage 100V) at a relative temperature of 93 ± 3 ℃

Insulation resistance at high temperatures: The insulation resistance (measured per meter) between the thermal electrode (including the double branch type) and the protective tube and the double branch thermal electrode of a thermocouple at high temperatures should be greater than the values specified in the table below.

8、 Selection List: