Industrial thermocouples are a type of temperature sensor typically used in conjunction with display instruments, recording instruments, and electronic regulators. It can directly measure the surface temperature of liquid vapor and gas media, as well as solids, ranging from 0 ℃ to 1800 ℃ in various production processes.
According to national regulations, our company produces prefabricated thermocouples such as Platinum Rhodium 30-Platinum Rhodium 6, Platinum Rhodium 10 Platinum, Nickel Chromium Nickel Silicon, Nickel Chromium Copper, etc. that comply with IEC international standard graduation numbers.
Thermocouples typically consist of temperature sensing elements, mounting fixtures, and junction boxes as their main components.













Measurement range and allowable error range

model	Graduation	Tolerance level
		Grade I		grade ii
		Allowable deviation	Temperature measurement range ℃	Allowable deviation	Temperature measurement range ℃
WRN	K	±1.5℃	-40~+375	±2.5℃	-40~+333
		±0.004（t）	375~1000	±0.0075（t）	333~1200
WRM	N	±1.5℃	-40~+375	±2.5℃	-40~+333
		±0.004（t）	375~1000	±0.0075（t）	333~1200
WRE	E	±1.5℃	-40~+375	±2.5℃	-40~+333
		±0.004（t）	375~800	±0.004（t）	333~900
WRF	J	±1.5℃	-40~+375	±2.5℃	-40~+333
		±0.004（t）	375~750	±0.004（t）	333~750
WRC	T	±0.5℃	-40~+125	±1℃	-40~+133
		±0.004（t）	125~350	±0.0075（t）	133~350
WRP	S			±2.5℃	0~+600
				±0.0025（t）	600~1300
WRQ	R			±2.5℃	0~+600
				±0.0025（t）	600~1300
WRR	B			±2.5℃	0~+600
				±0.0025（t）	600~1600

Note: t is the measured temperature value of the temperature sensing element (℃)

Thermocouple time constant

Thermal inertia level	Time constant (seconds)	Thermal inertia level	Time constant (seconds)
Ⅰ	90-180	Ⅲ	10-30
Ⅱ	30-90	Ⅳ	＜10

Thermocouple nominal pressure: generally refers to the static external pressure that the protective tube can withstand and rupture under working conditions.
Small insertion depth of 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 megohms (voltage 100V). Thermocouples with splash proof junction boxes have an insulation resistance of ≥ 0.5 megohms (voltage 100V) when the relative temperature is 93 ± 3 ℃
Insulation resistance at high temperatures: For thermocouples, the insulation resistance (per meter) between the hot electrode (including double branch) and the protective tube, as well as between the double branch hot electrodes, should be greater than the values specified in the table below.

Designated long-term use temperature (℃)	Test temperature (℃)	Insulation resistance value (Ω)
≥600	600	72000
≥ 800	800	25000
≥1000	1000	5000

WR□	Thermocouple standard type
1	mark	Thermocouple category		Graduation
	N	Nickel chromium nickel silicon		K
	M	Nickel chromium silicon nickel silicon		N
	E	Nickel chromium copper nickel		E
	F	Iron copper nickel		J
	C	Copper Copper Nickel		T
	P	Platinum rhodium 10 platinum		S
	Q	Platinum rhodium 13 platinum		R
	R	Platinum rhodium 30- Platinum rhodium 6		B
	W	Tungsten Rhenium 3-Tungsten Rhenium 25		WRe3/25
	2	mark	Number of thermocouple pairs
		1	Single support type (can be unmarked)
		2	Double branch type
		3	mark	Install fixed devices
			1	No fixed device
			2	Fixed thread
			3	Movable flange
			4	Flange
			5	Flexible tube connector type
			6	Fixed thread cone form
			7	Straight pipe joint type
			8	Fixed threaded pipe joint type
			9	Active threaded pipe joint type
			4	mark	Form of junction box
				2	Splash proof type
				3	Waterproof type
				4	Explosion proof type
				5	mark	Diameter of protective tube (mm)
					0	Ф16
					1	20 (S/R/B type thermocouple with a double-layer tube of 25)
					2	Ø 16 (high aluminum tube, limited to K and N type thermocouples)
					3	Ø 25 (high aluminum tube, limited to K and N type thermocouples)
						Special instructions (diameter marked with Ø size)

1. Our company promises that if you purchase our products, during the one-year warranty period, if you receive notification from the user about such defects, our company will unconditionally provide free repair or replacement for products that are indeed defective
2. We promise to handle the customer's technical questions within one working day.
3. We promise to provide test results within 3 working days and complete the repair within 7 working days for the instruments that need to be returned to the factory for repair.
4. Within 2 weeks after returning the instrument to the customer, conduct a follow-up visit to the user and provide free consultation on automation related technologies.