Product Name: J-type thermocouple, J-type armored thermocouple, J-type anticorrosive thermocouple, assembly J-type thermocouple
Product No.: 10333-193
Product model: J
Updated on: September 22, 2009
Manufacturer: thermocouple, thermal resistance, bimetal thermometer, polytetrafluoroethylene, PTFE gasket -- Shanghai Feilong instrument and Electrical Co., Ltd
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Product details
WR series industrial thermocouples, as temperature measuring sensors, are usually used in combination with temperature transmitters, regulators and display instruments to form a process control system, which can directly measure or control the temperature of fluid, steam, gas medium and solid surface in the range of 0-1800 ℃ in various production processes.
When the two ends of two different components of the conductor are connected to the composite circuit, when the temperature of the two junction points is different, the thermal current will be generated in the circuit. If there is a temperature difference between the working end and the reference end of the thermocouple, the display instrument will indicate the temperature corresponding to the thermoelectric potential generated by the thermocouple.
The thermoelectric dynamic heat of thermocouples will increase with the increase of the temperature at the measuring end. Its size is only related to the thermocouple material and the temperature at both ends, and has nothing to do with the length and diameter of the thermoelectric pole.
The shapes of various thermocouples are often very different due to their needs, but their basic structures are generally the same, usually composed of the main parts such as thermal electrode, insulating sleeve protection tube and junction box.
Main technical characteristics
Measurement range and basic error limit
Thermocouple category | Code name | Graduation | measuring range | Basic error limit |
Nichrome constantan | WRK | E | 0-800℃ | ±0.75%t |
Nickel chromium nickel silicon | WRN | K | 0-1300℃ | ±0.75%t |
Platinum rhodium 40 platinum | WRP | S | 0-1600℃ | ±0.25%t |
Platinum rhodium 30 - platinum rhodium 6 | WRR | B | 0-1800℃ | ±0.25%t |
Note: t is the measured temperature value of temperature sensing element (℃)
Thermocouple time constant
Thermal inertia level | Time constant (seconds) | Thermal inertia level | Time constant (seconds) |
Ⅰ | 90-180 | Ⅲ | 10月30日 |
Ⅱ | 30-90 | Ⅳ | <10 |
(96 bytes) nominal pressure of thermocouple: generally refers to the static external pressure that the protective tube can bear under the working temperature and break.
(96 bytes
) minimum insertion depth of thermocouple: not less than 8-10 times of the outer diameter of its protective sleeve (except for special products)
(96 bytes) insulation resistance: when the ambient air temperature is 15-35 ℃, and the relative humidity is less than 80%, the insulation resistance ≥ 5 megohm (voltage 100V). For thermocouple with splash proof junction box, when the relative temperature is 93 ± 3 ℃, the insulation resistance is ≥ 0.5 megohm (voltage 100V)
Aniu.gif (96 bytes) insulation resistance at high temperature: under high temperature, the insulation resistance (per meter) between the thermal electrode (including double branch type) and the protection tube as well as the double branch thermal electrode of the thermocouple shall be greater than the value specified in the table below.
Specified long-term service temperature (℃) | Test temperature (℃) | Insulation resistance (Ω) |
≥600 | 600 | 72000 |
≥ 800 | 800 | 25000 |
≥1000 | 1000 | 5000 |
Installation and use of thermocouples
The installation site of thermocouple shall be convenient for construction and maintenance. The temperature at the junction box shall not be more than 100 ℃ near the furnace door, or near the heating body and strong magnetic field. The installation position shall be vertical as much as possible, but it must be installed at an oblique angle when there is flow rate. The outlet of junction box shall be downward.
The thermocouple with porcelain protection tube must avoid sudden cooling and heating to prevent bursting. During installation, the place that does not hinder the movement of the heated object shall be selected. The temperature of the liquid shall not be measured by the porcelain tube.
The thermocouple shall be wired according to regulations, the lead shall avoid heat source, and the polarity of compensation conductor shall not be reversed during wiring. Check the condition of protective pipe frequently, and take measures immediately in case of oxidation or deformation. Check regularly.
Instructions for ordering
When ordering, users should note: (1) product name (2) product model (3) graduation number (4) material and diameter of protective tube (5) length L and insertion depth 1 (6) quantity (7) fixed thread M (8) special technical requirements.