Overview
Industrial thermocouple assembly as a temperature sensor, usually,
and display instruments, recording instruments and supporting the
use of electronic regulator. Thermocouple assembly can be directly
measured from a variety of production range of 0to 1800of liquid
vapor, gas and solid surface temperature
According to state regulations, the production company dividing
line with international standards IEC platinum and rhodium No. 30 -
6 platinum and rhodium, platinum and rhodium 10 - platinum, nickel,
chromium - nickel silicon, nickel, chromium - constantan
thermocouple assembly, etc.
Assembly thermocouple temperature sensing element is usually to
install fixtures and junction boxes and other major parts
Measuring range and allowable error range
Thermocouple types | Code | Dividing number | Measuring range | Basic error limit |
Nickel chrome－Constantan | WRK | E | 0－800℃ | ±0.75%t |
Nickel chrome－Ni Si | WRN | K | 0－1300℃ | ±0.75%t |
Platinum and rhodium 13 -Platinum | WRB | R | 0-1600℃ | ±0.25%t |
Platinum and rhodium 10 －Platinum | WRP | S | 0－1600℃ | ±0.25%t |
Platinum and rhodium 30 －Platinum and rhodium 6 | WRR | B | 0－1800℃ | ±0.25%t |
Note: t is the measured temperature sensing element temperature (
Thermocouple time constantLevel of thermal inertia | Time constant (seconds） | Time constant | Time constant (seconds） |
Ⅰ | 90－180 | Ⅲ | 10－30 |
Ⅱ | 30－90 | Ⅳ | ＜10 |
Thermocouple Pressure: generally refers to the working temperature
protection tube can withstand external pressure and the rupture of
the static
Thermocouple minimum insertion depth: the protective casing should
be not less than 8-10 times the diameter (special exceptions listed
products）
Insulation resistance: When the ambient air temperature is 15-35 ℃,
relative humidity "80%,5 megohms insulation resistance (voltage
100V). Junction box with a splash-type thermocouple, when the
relative temperature of 933 ℃, the insulation resistance of0.5 Mohm
(voltage 100V）
Insulation resistance under high temperature: thermocouples at high
temperatures, the hot electrode (including double-vessel type) and
the protection tube and double-vessel thermal insulation resistance
between the electrodes (per meters) should be greater than the
value specified in the following table
Prolonged use of prescribed temperature | Test temperature | Insulation resistance |
≥600 | 600 | 72000 |
≥ 800 | 800 | 25000 |
≥1000 | 1000 | 5000 |
