A thermocouple chart is a practical tool for the electronic query of temperature index. It is used by technicians who are engaged in automatic control of the production process.

To simply look at it means: when 0 is the reference temperature and the measured temperature is the sum of the row and column temperatures, the measured thermoelectric potential is the value.

thermocouple chart

How do you read a K type thermocouple table?

In the thermocouple chart, the first row and the first column are all temperature values.
The rows are incremented by 10 degrees per grid.
The columns are incremented by 100 degrees per grid.
The intersection of the row and the column is the thermoelectric potential value at the current temperature.

Take the S-type couple to read the thermoelectric potential value at 280 degrees Celsius for example: first find 200 degrees from the first column, and draw a straight line to the right.
Then find 80 degrees from the first line and draw a straight line down. Where the two lines meet, the thermoelectric potential value at 280 degrees is 2.141 millivolts.

Type K thermocouple chart

K Reference terminal temperature: 0℃, 10 degrees μν value

0102030405060708090
003977981203161120222436285032663681
1004095450849195327573361376539693973387737
200813785378938934197451015110560109691138111793
30012207126231303913456138741429214712151321555215974
40016395168181724117664180881851318938193631978820214
50020640210662149321919223462277223198236242405024476
60024902253272575126176265992702227445278672828828709
70029128295472996530383307993121431629320423245532866
80033277336863409534502349093531435718361213652436925
90037325377243812238519389153931039703400964048840879
100041269416574204542432428174320243585439684434944729
110045108454864586346238466124698547356477264809548462
120048828491924955549916502765063350990513445169752049
13005239852747530935343953782541255446654807
  

  

Type N thermocouple chart

N reference terminal temperature: 0℃, 10 degrees μν value

0102030405060708090
00261525793106513401619190221892480
1002774307233743680398943024618493752595585
2005913624565796916725575977941828886378988
300934196961005410413107741113611501118671223412603
40012974133461371914094144691484615225156041598416336
50016748171311751517900182861867219059194471983520224
60020613210032139321784221752256622958233502374224134
70024527249192531225705260982649126883272762766928062
80028455288472923929632300243041630807311993159031981
90032371327613315133541339303431934707350953548235869
100036256366413702737411377953817938562389443932639706
110040087404664084541223416004197642352427274310143474
120043846442184458844958453264569446060464254678947152
130047513
  

  

  

  

  

  

  

  

Type E thermocouple chart

E Reference terminal temperature: 0℃, 10 degrees μν value

0102030405060708090
0059111921801241930473683432949835646
10063176996768383779078978710501112221194912681
20013419141611490915661164171717817942187101948120256
30021033218142259723383241712496125754265492734528143
40028943297443054631350321553296033767345743538236190
50036999378083942640236410454185342662434704427845085
60045085458914669747502483064910949911507135151352312
70053110539075470355498562915708357873586635945160237
80061022618066258863368641476492465700664736724568015
90068783695497031371075718357259373350741047485775608
100076358
  

  

  

  

  

  

  

  

  

Type J thermocouple chart

J Reference terminal temperature: 0℃, 10 degrees μν value

0102030405060708090
0050710191536205825853115364941864725
10052685812635969077457800885609113966710222
20010777113321188712442129981355314108146631521715771
30016325168791743217984185371908919640201922074321295
40021846223972294923501240542460725161257162627226829
50027388279492851129075296423021030782313563193332513
60033096336833427334867354643606636671372803789338510
70039130397544038241013416474228342922435634420744852
80045498461444679047434480764871649354499895062151249
90051875524965311553729543215494855553561555675357349
100057942585335912159708602936087661459620396261963199
110063777643556493365510660876666467240678156839068964
120069536
  

  

  

  

  

  

  

  

  

Type T thermocouple chart

T reference terminal temperature: 0℃, 10 degrees μν value

0102030405060708090
003917891196161120352467290833573813
1004277474952275712620467027207771882358757
200928698201036010905114561201112572131371370714281
300148601544316030166211721717816
  

  

  

  

Type S thermocouple chart

S Reference terminal temperature: 0℃, 10 degrees μν value

0102030405060708090
0055113173235299365432502573
10064571979587295010291109119012731356
2001440152516111698178518731962205121412232
3002323241425062599269227862880297430693164
4003260335634523549364537433840393840364135
5004234433344324532463247324832493350345136
6005237533954425544564857515855596060646169
7006274638064866592669968056913702071287236
8007345745475637672778278928003811482258336
9008448856086738786889990129126924093559470
10009585970098169932100481016510282104001051710635
110010754108721099111110112291134811467115871170711827
120011947120671218812308124291255012671127921291313034
130013155132761339713519136401376113883140041412514247
140014368144891461014731148521497315094152151533615456
150015576156971581715937160571617616296164151653416653
160016771168901700817125172451736017477175941771117826

Type R thermocouple chart

R Reference terminal temperature: 0℃, 10 degrees μν value

0102030405060708090
0054111171232296363431501573
10064772380087995910411124120812941381
2001469155816481739183119232017211222072304
3002401249825972696279628962997309932013304
4003408351236163721382739334040414742554363
5004471458046904800491050215133524553575470
6005583569758125926604161576273639765076625
7006743686169807100722073407461758377057827
8007950807381978321844685718697882389509077
9009205933394619590972098509980101111024210374
100010506106381077110905110391117311307114421157811714
110011850119861212312260123971253512673128121295013089
120013228133671350713646137861392614066142071434714488
130014629147701491115052151931533415475156161575815899
140016040161811632316464166051674616887170281716917310
150017451175911773217872180121815218292184311857118710
160018849189881912619264194021954019677198141995120087
170020222203562048820620207492087721003
  

  

  

Type B thermocouple chart

B reference terminal temperature: 0℃, 10 degrees μν value

0102030405060708090
00-2-3-2026111725
100334353657892107123140159
200178199220243266291317344372401
300431462494529561596632669707746
40078682787091395710021048109511431192
5001241129213441397145015051560161716741732
6001791185119121974203621002164223022962363
7002430249925692639271027822855292830033078
8003154323133083387346635463626370837903873
9003957404141264212429843864474456246524742
10004833492450165109520252975391548755835680
11005777587559736073617262736374647565776680
12006783688769917096720273087414752176287736
13007845795380638172828383938504861687278839
14008952906591789291940595199634974898639979
150010094102101032510441105581067410790109071102411141
160011257113741149111608107251184211959120761219312310
170012436125431265912776128921300813124132391335413470
1800135851369913814
  

  

  

  

  

  

  

Download: K thermocouple chart

The working principle of thermocouple (thermocouple principle)

What is a thermocouple?
This is to start with the principle of thermocouple temperature measurement. The thermocouple is a kind of temperature sensing element and a primary instrument. It directly measures temperature and converts the temperature signal into a term electromotive force signal. It is converted into a term electromotive force signal by an electrical instrument (secondary instrument). The temperature of the measured medium.

The basic principle of thermocouple temperature measurement is that two different components of material conductors form a closed loop. When there is a temperature gradient at both ends, there will be a current passing through the loop, and then there is Seebeck electromotive force-term electromotive force between the two ends. This is the so-called Seebeck effect.

Two homogeneous conductors with different compositions are term electrodes, the end with a higher temperature is the working end, and the end with a lower temperature is the free end, which is usually at a certain constant temperature. According to the functional relationship between term electromotive force and temperature, a thermocouple index table is made. The index table is obtained when the free end temperature is at 0℃. Different thermocouples have different index tables.

When the third metal material is connected in the thermocouple circuit, as long as the temperature of the two junctions of the material is the same, the thermoelectric potential generated by the thermocouple will remain unchanged, that is, it will not be affected by the third metal in the circuit. Therefore, when the thermocouple measures the temperature, it can be connected to the measuring instrument, and after the term electromotive force is measured, the temperature of the measured medium can be known.

The working principle of thermocouple:

Two conductors with different components (called thermocouple wires or thermoelectrodes) are connected at both ends to form a loop. When the temperature of the junction is different, an electromotive force will be generated in the loop. This phenomenon is called the thermoelectric effect. And The electromotive force is called thermoelectric force.

Thermocouples use this principle for temperature measurement. One end that is directly used to measure the temperature of the medium is called the working end (also called the measuring end), and the other end is called the cold end (also called the compensation end). The cold end and the display instrument or When the matching instrument is connected, the display instrument will point out the thermoelectric potential generated by the thermocouple.

A thermocouple is actually a kind of energy converter, which converts heat energy into electrical energy. Use the generated thermoelectric potential to measure temperature. Regarding the thermoelectric potential of a thermocouple, you should pay attention to the following issues:

  1. The thermoelectric potential of a thermocouple is a function of the temperature difference between the two ends of the thermocouple. It is not a function of the temperature difference between the two ends of the thermocouple;
  2. The size of the thermoelectric potential generated by the thermocouple. When the material of the thermocouple is uniform, it has nothing to do with the length and diameter of the thermocouple, but is only related to the composition of the thermocouple material and the temperature difference between the two ends;
  3. When the two thermocouple wires of the thermocouple have determined the material composition. The thermoelectric potential of the thermocouple is only related to the temperature difference of the thermocouple. If the temperature of the cold junction of the thermocouple remains constant, the thermoelectric potential of the thermocouple is only Single-valued function of working end temperature.

Sino-Inst, Manufacturer for Thermocouples, like: Armoured thermocouple, assembly thermocouple, explosion-proof thermocouple, etc.

Sino-Inst’s Thermocouples, made in China, Having good Quality, With better price. Our Temperature measurement instruments are widely used in China, India, Pakistan, the US, and other countries.

Request a Quote

Please provide your measurement parameters or details. Sino-Instrument support customer customization and OEM

Leave a Reply

Your email address will not be published. Required fields are marked *