Thermocouple wire calculation
Thermocouple (thermocouple temperature transmitter) thermocouple, used in measuring and converting devices, and control systems and automation of heating, ventilation and air conditioning systems.
The advantages of thermocouples
- Wide temperature measurement range
- Measurement of high temperatures up to 1800 — 2200°C
- Measurement of low t° -50°C
Disadvantages
- A precision better than 1 °C are difficult to achieve, it is necessary to use resistance thermometers or thermistors.
- The readings affected by temperature loose ends that need to be amended.
- The error arises from change of temperature cold junction
- the Peltier effect (at the time of deposition, it is necessary to eliminate current flow through the thermocouple, because this current cools the hot and warms the cold)
Thermocouple types
Requirements for thermocouple are determined by GOST 6616−94.
- platinoidy — platinum — ТПП13 — Type R; ТПП10 — Type S
- platinoidy — platinite — TPR — B
- iron-Konstantinova (iron-megynkelly) TFA — Type J
- copper-Konstantinova (copper-megynkelly) Tmcn — Type T
- have nicrosil-nicelove (nickelchromium-nickelchromium) TNN — Type N.
- chromel-alyuminevye THA K Type
- chromel-Konstantinovy DCN — Type E
- chromel-kopelove — TCA — L
- copper — kopeleva — TMK — M
- Silk-sulinowie — TSS — Type I
- Wolframite — wolframite — TVR — Type a-1, A-2, A-3
Comparison of thermocouples
The table below describes properties of several different thermocouple types. Within the columns is exactly T is the temperature of the hot compound, in degrees Celsius. For example, a thermocouple with an accuracy of±0.0025 G-T would be accurate To±2.5°C to 1000 °C.
| The type of thermocouple IEC | Temperature range °C (long-term) | Temperature range °C (short-term) | Tolerance class 1 (°C) | Accuracy class 2 (°C) |
|---|---|---|---|---|
| K (alumel — chromel) | 0 to +1100 | -180 to +1300 | ±1.5 between -40 °C and 375 ░ C ▒ 0.004 xT from 375 °C to 1000 °C | ±2.5 between -40 °C and 333 °C ±0.0075 xT from 333 °C to 1200 °C |
| J | 0 to +700 | -180 to +800 | ±1.5 between -40 °C and 375 ░ C ▒ 0.004 xT from 375 °C to 750 °C | ±2.5 between -40 °C and 333 °C ±0.0075 xT from 333 °C to 750 °C |
| N | 0 to +1100 | -270 to +1300 | ±1.5 between -40 °C and 375 ░ C ▒ 0.004 xT from 375 °C to 1000 °C | ±2.5 between -40 °C and 333 °C ±0.0075 xT from 333 °C to 1200 °C |
| R | 0 to +1600 | -50 to +1700 | ±1.0 from 0 °C to 1100 °C ±[1 + 0.003 x (T — 1100)] from 1100 °C to 1600 °C | ±1.5 from 0 °C to 600 ░ C ▒ 0.0025 xT between 600 °C to 1600 °C |
| S | 0 to 1600 | -50 to +1750 | ±1.0 from 0 °C to 1100 °C ±[1 + 0.003 x (T — 1100)] from 1100 °C to 1600 °C | ±1.5 from 0 °C to 600 ░ C ▒ 0.0025 xT between 600 °C to 1600 °C |
| B | +200 to +1700 | 0 to +1820 | ±0.0025 xT between 600 °C to 1700 °C | |
| T | -185 to +300 | -250 to +400 | ±0.5 -40 °C to 125 °C}} ±0.004 xT between 125 °C to 350 °C | ±1.0 from -40 °C to 133 °C}} ±0.0075 xT from 133 °C to 350 °C |
| E | 0 to +800 | -40 to +900 | ±1.5 between -40 °C and 375 ░ C ▒ 0.004 xT from 375 °C to 800 °C | ±2.5 between -40 °C and 333 °C ±0.0075 xT from 333 °C to 900 °C |
Wire and strip for thermocouples
Characteristics of the alloy Alumel Nmcak2−2-1- Characteristics of the alloy Chromel NH9,5
- The characteristics of the alloy, Copel Mnmc43−0,5
- Characteristics of the alloy Constantan Mnmc43−0,5
- Electrical resistance and weight of the thermocouple
- Experience in the use of wolframtones thermocouples ВР5/20 in high temperature thermometry
Our consultant will save your time!
Vitaliy
sales department
+38 (095) 209-60-73