Omega RD260A instruction manual Temperature Compensation for Thermocouple Signal

4.8 Maintenance

Power terminal

L

N

Three lead wires should have the same resistance values.

B A

1	b
2
3

Decade resistance box

Input terminals

(for RTD)

Temperature Signal as RTD for Pen model

(for Dot-printing model, the wire connection exchanges between the terminal B and b.)

Temperature Compensation for Thermocouple Signal

Copper wires Thermocouple wires or extension wires Power terminals

			L
+	+	+	N
—	Meter	Couple
	—	—

4. DAILY

DC voltage standard

Copper wires

	— +
	1
	2
Thermocouple wires	3

Ice pieces packed to maintain the temperature at 0ßC

OPERATION/MAINTENANCE

(reference junction compensator Model TRCIII)

Reference Junction Compensation for Thermocouple Input

A DC voltage generated by a thermocouple differs from a value calculated from the table of thermo- electromotive force (EMF) because the table is based on the 0˚C reference temperature but the temperature at the recorder input terminal is generally equal to the room temperature.

The recorder measures the temperature at the input terminal for compensation; when the input terminals are shorted (equivalent to 0˚C of the thermocouple in the EMF table), the recorder indicates the temperature at the input terminal.

For calibrating a recorder, an input voltage after the compensation (after subtraction of the compensating voltage) should be applied to the recorder; an example is shown in (thTRCIII reference junction compensator is used).

Reference Temperature Compensating Connection for Pen model (same as Dot-printing model)

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