- Phone
-
Address
No. 650 Lingshi Road, Jing'an District, Shanghai
Shanghai Automation Instrument Co., Ltd
No. 650 Lingshi Road, Jing'an District, Shanghai
WRNK2-321 Armored Thermocouple Shanghai Automation Instrument Factory 3
The thermoelectric potential of the armored thermocouple will increase with the temperature rise at the measuring end. The magnitude of the thermoelectric potential is only related to the material of the armored thermocouple conductor and the temperature difference between the two ends, and is independent of the length and diameter of the thermoelectric electrode.
working principle
The working principle of armored thermocouples is to weld two conductors with different compositions at both ends to form a circuit. The direct temperature measuring end is called the measuring end, and the wiring end is called the reference end. When there is a temperature difference between the measuring end and the reference end, a thermal current will be generated in the circuit. When connected to a display instrument, the instrument will indicate the corresponding temperature value of the thermoelectric potential generated by the thermocouple.

The structure of armored thermocouples is made up of conductors, insulated magnesium oxide, and 1Cr18Ni9Ti stainless steel protective tubes that have been drawn multiple times. Armored thermocouple products mainly consist of junction boxes, terminal blocks, and armored thermocouples, and are equipped with various installation and fixing devices.
Armored thermocouples are divided into two types: insulated and shell connected.
Main technical indicators
Temperature measurement range and accuracy
Category |
code name |
graduation mark |
Outer diameter of casing mm |
Common temperature℃ |
Zui High Operating Temperature℃ |
allowable deviation△t |
|
measurement range℃ |
Allowable deviation |
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Nickel chromium copper nickel |
WREK |
E |
≥Φ3 |
600 |
700 |
0~700 |
±2.5℃Or ± 0.75% t |
Nickel chromium nickel silicon |
WRNK |
K |
≥Φ3 |
800 |
900 |
0~900 |
±2.5℃Or ± 0.75% t |
Copper Copper Nickel |
WRCK |
T |
≥Φ3 |
350 |
400 |
<-200 |
Not specified |
-40~350 |
±0.75%t |
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Note: 1) t is the value of the measured temperature.
2) The production of T-shaped dividing marks requires negotiation and ordering with the manufacturer.
Armored thermocouple thermal response time
When there is a step change in temperature, the output of the thermocouple changes to 50% of the step change, and the time required is called the thermal response timeT0.5express
The thermal response time of armored thermocouples shall not exceed the specifications in the following table:
Thermal response timeT0.5S |
Shell type |
Insulated type |
Diameter of casing (min) | ||
2.0 |
0.4 |
0.5 |
3.0 |
0.6 |
1.2 |
4.0 |
0.8 |
2.5 |
5.0 |
1.2 |
4.0 |
6.0 |
2.0 |
6.0 |
8.0 |
4.0 |
8.0 |
insulation resistance
When the ambient air temperature is 20 ± 15℃When the relative humidity is not greater than 80%, the insulation resistance value between the thermocouple wire and the outer sleeve of the insulated armored thermocouple should comply with the provisions in the following table.
Sleeve diameter mm |
Test voltage V-D.C |
Insulation resistance M Ω. m |
0.5~1.5 |
50±5 |
≥1000 |
>1.5 |
500±50 |
≥1000 |
WRNK2-321 Armored Thermocouple Shanghai Automation Instrument Factory 3Model representation
W |
R |
specification |
content |
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N |
Nickel chromium nickel silicon |
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E |
Nickel chromium copper nickel |
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C |
Copper Copper Nickel |
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Temperature measuring element material |
Armored type |
- |
1 |
Non fixed device type |
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2 |
Fixed card sleeve thread |
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3 |
Movable card sleeve thread |
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4 |
Fixed card sleeve flange |
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5 |
Movable card sleeve flange |
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|
An pretend solid fixed form formula |
0 |
Insulated type |
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2 |
Shell type |
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3 |
waterproof type |
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8 |
handle-type |
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8 |
Small junction box |
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9 |
With compensating wire |
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|
pick up line box form formula |
1 |
Insulated type |
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2 |
Shell type |
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8 |
Shell type(handle-type) |
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9 |
Insulated type(handle-type) |
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Workplace format |
3 |
3 pairs |
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4 |
4 pairs |
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5 |
5 pairs |
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6 |
6 pairs |
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many Correct formula |
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W |
R |
□ |
K |
- |
□ |
□ |
□ |
□ |
|
Standard specifications for outer diameter and nominal length of armored thermocouples
Armored thermocouple outer diameter dmm | ||||
Φ8 |
Φ6 |
Φ5 |
Φ4 |
Φ3 |
|
50 75 100 150 200 250 300 400 500 750 1000 |
50 75 100 150 200 250 300 400 500 750 1000 1250 1500 2000 |
50 75 100 150 200 250 300 400 500 750 1000 1250 1500 2000 2500 3000 4000 |
50 75 100 150 200 250 300 400 500 750 1000 1250 1500 2000 2500 3000 4000 5000 7500 1000 |
50 75 100 150 200 250 300 400 500 750 1000 1250 1500 2000 2500 3000 4000 5000 7500 1000 1500 |
Note: 1. The nominal L of the insulated armored thermocouple with a diameter of Φ 3mm shall not exceed 10000mm
2. Armored thermocouples with a diameter of d ≤ Φ 5mm and equipped with splash proof or waterproof junction boxes. The thermocouple is exposed from the equipment, and users must install auxiliary supports such as brackets to increase its rigidity, ensure fastening, and prevent the junction box from shaking and damaging the thermocouple due to vibration.
3. The armored thermocouple with a diameter of Φ 2mm must be ordered through negotiation with our factory.