Intab PC-Logger 3100i, How To Use Manual, Page: 14 / 49

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INTAB Interface-Teknik AB
5.4.1 Ranges and linearization
Different types of thermocouples have differing levels of output. They
therefore have differing fields of application most often depending on the
temperature range to be measured.
What two materials make up the couple may also be of a certain importance.
We will however, have to assume that this is known to the user.
Below is a short summary of the properties of the most common types of
thermocouples. It is included to help in selecting type and range for your
application.
”K” is the most common type.
”Cold Junction” = 0°C
TYPE mV at
200°C mV at
600°C mV at
1200°C
MAX temp °C
K 8.137 24.902 48.828 1370
N 5.912 20.609 43.836 1300
J 10.777 33.096 ---------- 760
T 9.286 --------- ---------- 400
S 1.440 5.237 11.947 1760
R 1.468 5.582 13.224 1760
Thermocouples are non-linear. This is corrected by the internal program of the
”3100i”.
Thermoelectric voltage is measured (in mV) and then adjusted for the cold
junction temperature according to the type specified. This adjusted voltage is
then used as input variable to a linearizing table. The table (one for each
thermocouple type) is constructed so that its contribution to the measurement
error is negligible.