Calibration 5.4 - Partlow MRC 7800 Installation, Wiring, Operation Manual

Calibration 5.4

CAUTION: Do not attempt any calibrations without the proper test equipment that meets or exceeds the specifications
listed.
To enter the calibration mode it must first be turned on in the Enable mode (page 25). Once
enabled, press and release the SCROLL key until CAL appears on the display, then press the
DOWN key to enter the mode. The display will change to CAL1. Press the SCROLL key to
advance the display to the other calibration modes available. Table 5-1 provides a listing of
field calibration routines. All instruments are calibrated prior to shipment from factory.
TABLE 5-1 CALIBRATION PROCEDURES
Calibration
Procedure Description
CAL1 Reinitialization of program and tuning values.
CAL2 Main calibration necessary for all input types.
CAL6 & 7 Factory use only.
CAL8 Data Logger Re-initialization.
CAL9 Pen position calibration used to calibrate pens to chart.
5.4.1 CAL 1 PARAMETER RE-INITIALIZATION
This routine is used to clear all information in the Program, Alarm Set, and Preset modes. All
parameters will be reset to default values. Before performing this procedure, make sure that
the Program, Alarm, and Preset values are written down so that they can be re-entered after
Calibration 1 is completed. No test equipment required.
With CAL1 displayed, press and hold the DOWN key, then press the SCROLL key. The
display will momentarily blank; release the keys. Upon completion of the routine, CAL1 will
re-appear on the display.
5.4.2 CAL 2 MAIN CALIBRATION
This routine determines and saves calibration values which correct for component variations
relating to the basic measuring function of the unit. A 100.00 mVDC ± .01 mVDC source is
required for testing. Make sure that the Processor board jumpers JU4 and JU5 are in the
non-volt positions. See Appendix A-1 (page 46) for proper positioning. After complet-
ing CAL2, be sure to re-position these jumpers to the appropriate position for your
input.
With CAL2 displayed, press and hold the DOWN key, then press the SCROLL key. Release
the keys when the instrument displays hLd1. Short the input terminals or apply 0.00 ± .01
mVDC to TB4 terminals 1 and 2. Press the DOWN key and dELy will appear for 10 seconds,
then SCAn will appear for 10 seconds. A calibration reference number will then appear, this
should be 0 ± 50. If this number falls outside these limits, press the SCROLL key and CAL2
will be displayed. Perform the calibration again. Repeat the calibration until the number falls
within the tolerance limits. If the number remains outside the limits, check the connections
and try the calibration again. If the number does not approach the tolerance limts, contact the
nearest representative or factory for assistance. With an acceptable reference number on the
display, remove the short and connect a 100.00, ± .01 mVDC source to the TB 4 terminals 1
and 2. Be sure to observe the proper polarity when connecting the source. Terminal 1 is
positive and terminal 2 is negative. (Continued on next page)
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