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Advanced Operation and Configuration
External Reference Junction
When using an external Reference Junction, MC5-IS measures or simulates the
thermovoltage using the “T/C Low V” terminals in the ET section. If the measuring/
simulating port is set to the External Reference Junction (ET: TCx(mea) or ET:
TCx(sim)), the following Reference Junction compensation methods are available:
0°C:
To be used when:
• The Reference Junction temperature is
fixed to 0°C (using, e.g. ice) and MC5-
IS is not used for measuring the Refer-
ence Junction temperature.
• The Reference Junction temperature is
controlled with 0°C set point.
• A compensation box is used and the
Reference Junction temperature setting
is 0°C.
• There is no Reference Junction com-
pensation in the measuring/simulation
circuit but 0°C is a good enough ap-
proximation.
Entered:
To be used when:
• The Reference Junction temperature is
fixed to a temperature that differs from
0°C.
• The Reference Junction temperature is
controlled and the controller’s set point
is not 0°C. Note: this method is of use
only if the accuracy of the controller is
better than MC5-IS’ own Reference
Junction Module.
• A compensation box is used and the
Reference Junction temperature setting
is other than 0°C.
• There is no Reference Junction com-
pensation in the measuring/simulation
circuit, but you want to manually enter
another Reference Junction tempera-
ture than 0°C.
Warning!
If you connect an RTD sensor to the ET
module’s R, RTD connectors, there is no
galvanic isolation between the thermo-
couple and the RTD sensor.
RTD sensor:
To be used when:
• The Reference Junction temperature is
measured using an RTD sensor con-
nected to MC5-IS’ RTD terminals.
Connection when measuring/simulating
thermovoltage using Reference Junction
compensation method RTD sensor:
T/C, Low V R, RTD
T/C INT. RJ
SENSOR MEASURE & SIMULATE
T/C
WIRES
ONLY
4 w meas
3 w measmeas/sim
T/C, Low V
T/C sensor
or a
T/C signal receiver
T/C materials Copper
T
ref
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