P
AGE
47
5.2.5 CAL 5 RTD INPUT
This procedure determines and saves calibration values which correct for component vari-
ations relating to RTD inputs. This calibration must be preceded by CAL2 to properly
calibrate the unit.
Test equipment needed will include a Decade Box (Resistance Substitution ) with .01%
resolution or equivalent. Make sure the jumpers JU1 (Processor Board), JU2 and JU3
(Options boards) are in the proper positions for RTD input. See Appendix A-2 (page 60) and
A-3 (page 61, 62).
With CAL5 displayed press and hold the DOWN key, then press the SCROLL key and
release both keys. hLd1 will then be displayed. Connect the Decade Box at 100 ohm setting
across the input terminals 1 and 3 and Jumper terminals 1 and 5. Press the DOWN key and
dELy will be displayed for up to ten seconds, then SCAn for ten seconds. When hLd2 is
displayed, connect 277 ohms to the input and press the DOWN key. Again dELy will display
for up to ten seconds, followed by SCAn for ten more seconds. CAL5 will be displayed after
the calibration is completed.
Error Recovery - See section 5.4 (page 51) for details about specific errors.
The Calibration mode can be exited any time the unit displays hLd1 or hLd2 by pressing the
SCROLL key.
5.2.6 CAL 6 COLD JUNCTION ON/OFF
With CAL 6 displayed, while pressing the DOWN ARROW key, press the SCROLL key. The
instrument will display C6 and the number of the mode in effect. Mode 0 is the normal
operating mode. The cold junction compensation is on. Mode 1 is the cold junction compen-
sation disabled (off). Pressing the UP ARROW or DOWN ARROW will change the mode
selection. The Mode 1 functions to facilitate input testing with a non-temperature compen-
sated millivolt source used to simulate thermocouple input.
