Input Calibration
5.4.3 RTD Inputs
Refer to Figure 5-4 and wire the controller according to the procedure given in Table 5-5.
Step
1
Connect the copper wires to the terminals for the input to be calibrated. See Figure
5-4.
Decade
Resistance
Box
Figure 5-4 Wiring Connections for RTD (Resistance Thermometer Device)
ATTENTION
Decade Resistance Boxes are usually not accurate enough to meet the 0.02% accuracy
requirement noted in Table 5-2. This can be overcome by performing a four-wire resistance
measurement with a precision DMM and then adjusting the Decade Box to the correct zero and
span resistance values as given in Table 5-1. Determine the proper zero and span resistance
settings prior to attaching the Decade Box to the instrument. For best accuracy, measure with
the DMM connected to the wire ends rather than directly to the Decade Box.
284
Table 5-5 Set Up Wiring Procedure for RTD Inputs
UDC3500 Universal Digital Controller Product Manual
Action
Copper Leads
Equal Length
28R
Input 3
29+
30-
31R
32+
Input 2
33-
34R
35+
Input 1
36-
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