Omega RD2800 Series User Manual page 126

21. MAINTENANCE
3
Connections
Connections depend upon the input types. Connect both standard and other tools to the measuring input
terminals to be adjusted.
Caution
Turn off the power source before starting connections
In order to prevent electric shock, turn off the power source before starting connections.
(1) In case of thermocouple input
＋
－
DC standard voltage
generator
The electromotive force of the thermocouple input is reduced by an amount proportional to the temperature
at the terminals. The recorder itself compensates (reference junction compensation) for this reduction. The
adjustment is executed by inputs based on the reference electromotive force (0°C reference). In case the
"RJ selection" is set to "1" (Enable) in the "Range/Printing range" programming, an amount equivalent to the
reference junction compensation has to be subtracted using a reference junction compensator.
(2) DC voltage input
（＋）
（－）
＋ －
Standard variable
resistor
4
Checking Method
Input the printing range (T) of 0%, 50% and 100% from a
standard tool and obtain an error (e) by reading the
measured values (M).
21.3 Measured Values Check
*Thermocouple of the same
type as the input type
Copper lead wire
Reference junction
compensator
1 2 3 4
Input terminals
－１２２－
(+)
Thermocouple wire *
( - )
Test tube
Silicon oil
Ice + distilled water
Vacuum bottle
(3) Resistance thermometer input
(A)
(B)
(B)
Standard variable
resistor
Error computation
e (%) =
1 2 3 4
Input terminals
1 2 3 4
Input terminals
M – T
X 100
T