K, N, J, E, T what is the difference between several kinds of thermocouple specific _ instrument
Nickel chrome -
Nickel silicon type K thermocouple nickel chrome -
Nickel silicon dosage of K type thermocouple is very inexpensive metal thermocouple, the sum of its use for other thermocouple.
The anode (
In the name of the chemical composition is: Ni: Cr = 90:10, the cathode (
In the name of the chemical composition is: Ni: Si = 97:3, minus its working temperature
K type thermocouple has advantages of good linearity, thermoelectric emfs, high sensitivity, good stability and uniformity, the oxidation resistance is strong, the advantages of cheap, can be used for oxidizing inert atmosphere.
Widely adopted for the user.
K type thermocouple cannot directly at high temperature for sulfur, reducing or reduction, oxidation atmosphere and vacuum alternately, also not recommended for people with weak oxidizing atmosphere.
Nickel chromium silicon -
N type thermocouple nickel chrome nickel silicon magnesium silicon -
Nickel N type thermocouple for inexpensive silicon magnesium metal thermocouple, thermocouple is a standardized, is developed in the early 70 s by Australian laboratory it overcome the K type thermocouple two important faults: K type thermocouple between 300 ~ 500 ℃ because of nickel-chromium alloy lattice thermoelectric emfs caused by short-range order of unstable;
At about 800 ℃ caused by nickel chrome preferential oxidation thermoelectric emfs instability.
The anode (
Chemical composition as follows: in the name of the Ni, Cr, Si = 84.
4, the cathode (
In the name of the chemical composition is: Ni: Si, Mg = 95.
For - 1, its working temperature
N type thermocouple has advantages of good linearity, thermoelectric emfs is larger, higher sensitivity, stability and good uniformity, oxidation resistance is strong, cheap, is not affected by short-range ordering etc, and its comprehensive performance is better than that of K type thermocouple, thermocouple is a kind of very promising.
N type thermocouple cannot be directly used at high temperature, reducing or reduction, oxidation atmosphere and vacuum alternately, is not recommended for people with weak oxidizing atmosphere.
Copper and nickel - J type thermocouple iron
Copper nickel J type thermocouple is also called the iron -
Constantan thermocouple, is also a kind of cheap cheap metal thermocouple.
It's the positive (
In the name of the chemical composition of pure iron, the cathode (
For copper and nickel alloy, has often been vaguely call constantan, its nominal chemical composition of: 55% copper and 45% nickel as well as small amounts of very important manganese, cobalt, iron and other elements, although it's called constantan, but differs from that of nickel and chromium -
Constantan and copper -
Constantan constantan, so can't use EN and TN to replace.
Constantan thermocouple measuring temperature area for -
200 ~ 1200 ℃, but usually use temperature range of 0 ~ 750 ℃ J type thermocouple has advantages of good linearity, thermoelectric emfs is larger, higher sensitivity, stability and uniformity is good, the advantages of cheap, widely used by users.
J type thermocouple can be used in the vacuum, oxidation, reduction and inert atmosphere, but iron anode oxidation at high temperature quickly, so the temperature is restricted, cannot be directly without reserve for curing atmosphere at high temperature.
Nickel chrome -
Copper and nickel E type thermocouple nickel chrome -
Copper and nickel E type thermocouple is also called the nickel chrome -
Constantan thermocouple, is also a kind of cheap metal thermocouple, the anode (
Nickel chrome 10 alloy, chemical composition is the same as the KP, the cathode (
For copper and nickel alloy, nominal chemical composition: 55% copper, 45% nickel and a small amount of manganese, cobalt, iron and other elements.
Temperature for the use of the thermocouple
E type thermocouple thermoelectric emfs, high sensitivity of all thermocouples, should be made of thermopile, measuring the temperature of the small change.
Not very sensitive to high humidity atmosphere corrosion, appropriate is used in the environment of high humidity.
E thermocouple has good stability and oxidation resistance is better than that of copper -
Lala, - of iron
Constantan thermocouple, the advantages of cheap, can be used for oxidizing and inert atmosphere, is widely used for the user.
E type thermocouple cannot directly at high temperature for sulfur, reducing atmosphere, the uniformity of the thermoelectric potential is poorer.
Copper nickel T thermocouple copper -
Copper nickel T thermocouple is also called copper -
Constantan thermocouple, is also a good measure of low-temperature inexpensive metal thermocouple.
It's the positive (
Is pure copper, anode (
For copper and nickel alloy, often as a constantan, chromium and nickel - it
- constantan constantan EN general, and iron
Constantan constantan Jacqueline Nottingham not general, although they are called constantan, copper -
The lid of the copper and nickel thermocouple temperature range of measurement for -
T thermocouple has advantages of good linearity, thermoelectric emfs is bigger, high sensitivity, good stability and uniformity, the advantages of cheap, especially in -
200 to 0 ℃ temperature zone, better stability and stability can small plus or minus 3 mu V, the low temperature test can be used as second class standard value transmit. in at low temperature.
T thermocouple of the anode copper poor oxidation resistance at high temperature, so the temperature limit is restricted.