Calibrating Thermocouples - Omron e5ck User Manual

CHAPTER 7 CALIBRATION

7.2 Calibrating Thermocouples

F Preparations
Connecting the
Cold Junction
Compensator
7–4
• Calibrate according to the type of thermocouple, thermocouple 1 group
(K1, J1, L1, E, N, W, PLII) and thermocouple 2 group (K2, K2, L2, R, S,
B, T, U).
• When calibrating, do not cover the bottom of the controller. Also, do not
touch the input terminals (Nos.6 and 7) or compensating conductor on
the E5CK T controller.
~
AC100-240V
(AC/DC24V )
5
SOURCE
4
3
2
1
• Set the cold junction compensator designed for compensation of inter
nal thrmocuples to 0_C. However, make sure that internal thermocou
ples are disabled (tips are open).
• In the above figure, STV refers to a standard DC current/voltage source,
and DMM refers to a precision digital multimeter.
However, note that DMM is required only when the transfer output
function is supported.
• Use the compensating conductor on the selected thermocouple. Howev
er, note that when thermocouple R, S, E, B, W and PLII is used, the cold
junction compensator and the compensating conductor can be substi
tuted with the cold junction compensator and the compensating conduc
tor for thermocouple K.
Correct process values cannot be obtained if you touch the contact ends of the com
pensating conductor during calibration of a thermocouple. Accordingly, short (en
able) or open (disable) the tip of the thermocouple inside the cold junction compen
sator as shown in the figure below to create a contact or non contact state for the
cold junction compensator.
Cold junction
compensator
0°C/32°F
E5CK-T
Compensating conductor
10
11 12
9
8
7
13 14
6
Compensating
DMM
conductor
Short
E5CK-T
Compensating conductor
STV
Cold junction
compensator
0_C/32_F
Cold junction
compensator
0°C/32°F
Open