Explosion-proof thermocouple

1. Explosion-proof thermocouple application

It is usually used in conjunction with display instruments, recording instruments, and electronic calculations. Directly measure the surface temperature of liquid, vapor and gaseous media and solids in the range of 0°C~1300°C where there are explosives such as hydrocarbons at the production site.

2. Features of explosion-proof thermocouple

       · Various explosion-proof forms with good explosion-proof performance;
       · Compression spring type temperature sensing element, good anti-vibration performance;
       · Large temperature measurement range;
       · High mechanical strength and good pressure resistance;

3. The working principle of explosion-proof thermocouple

  Explosion-proof thermocouples are designed to have sufficient strength such as junction boxes and other components based on the principle of gap explosion isolation. The parts that may generate sparks, arcs and dangerous temperatures are sealed in the junction box cavity. When an explosion occurs in the cavity, the flame can be extinguished and cooled through the gap of the joint surface, so that the flame and temperature after the explosion can not be transmitted outside the cavity, thereby performing an isolated explosion.

4. Main technical parameters of explosion-proof thermocouple

       Product performance standards
       IEC584
       IEC1515
       GB/T16839-1997
       JB/T5518-91
       GB3836

5. Normal temperature insulation resistance of explosion-proof thermocouple

The ambient temperature of the thermocouple is 20±15°C, the relative humidity is not more than 80%, and the test voltage is 500±50V (DC). Insulation resistance between electrode and outer tube>1000Ω.m

6. Explosion-proof thermocouple certification list

Explosion-proof level	Explosion-proof certificate number	Certification body
d‖BT4	GYB96450	NEPSI
d‖BT4	GYB96453	NEPSI
d‖CT5	GYB98339	NEPSI
d‖CT5	GYB97197	NEPSI
ia‖CT6	GYB99412	NEPSI

7. Measuring range and tolerance of explosion-proof thermocouple

Model number	Index number	Tolerance level
		I		II
		Tolerance value	Temperature range °C	Tolerance value	Temperature range °C
WRN	K	±1.5°C	-40~+375	±2.5 °C	-40~+333
		±0.004ltl	375~1000	±0.0075 ltl	333~1200
WRM	N	±1.5°C	-40~+375	±2.5°C	-40~+333
		±0.004 ltl	375~1000	±0.0075 ltl	333~1200
WRE	E	±1.5°C	-40~+375	±1.5°C	-40~+333
		±0.004 ltl	375~800	±0.004 ltl	333~900
WRF	J	±1.5°C	-40~+375	±1.5°C	-40~+333
		±0.004 ltl	375~750	±0.004 ltl	333~750
WRC	T	±1.5°C	-40~+125	±1°C	-40~+133
		±0.004 ltl	125~350	±0.0075 ltl	133~350

9. Types of electrical equipment

    Class I-electrical equipment for underground coal mines
    Class II-Electrical Equipment for Factory

10. Explosion-proof grade

The explosion-proof grades of explosion-proof thermocouples are divided into three grades A, B, and C according to the maximum safety gap used in explosive gas mixtures.

category	Level	Maximum test safety gap (MESG) mm
II	A	0.9≤MESG
	B	0.5<MESG<0.9
	C	MESG≤0.5

11. Temperature group of explosion-proof thermocouple

The temperature group of explosion-proof thermocouple is divided into T1-T6 according to the maximum allowable surface temperature of its exposed part

13. Junction box form of explosion-proof thermocouple

Temperature Group	Allowable maximum surface temperature ℃
T1	450
T2	300
T3	200
T4	135
T5	100
T6	85

12. Explosion-proof level of explosion-proof thermocouple

      EXdII□T□
      EXiaII□T□
  Protection level: IP65

13. Junction box form of explosion-proof thermocouple

13. Model naming method of explosion-proof thermocouple

15. Explosion-proof thermocouple, selection list

Explosion-proof thermocouple without fixing device	Fixed thread type explosion-proof thermocouple