West Control Solutions MRC 8000 - Manual (Page 52)

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5.4.7 CAL 9 PEN CALIBRATION
This procedure is used to calibrate the pen(s). No special test equipment required.
Valid inputs must be connected to TB 4 and TB 5 before performing this calibration. With CAL
9 displayed, push and hold the DOWN key, then press the SCROLL key . Release both keys
and the display will indicate PEn1. For 2 Pen instruments, press the DOWN key to toggle the
display between pen 1 and pen 2. With desired pen displayed, press the SCROLL key.
P.dn will be displayed while the selected pen is moved to it's "HOME" position (toward the
chart hub) with the decimal point flashing to indicate this mode. Once "Pen Home" is found,
the pen will move to the inner ring and PEnL will be displayed. At this point, one of two
adjustments may be made; Pen Arc or Zero and Span.
Pen Arc - To adjust the pen arc, the UP and DOWN keys are pressed simultaneously to draw
an arc for visual reference. The display will show P uP while the selected pen moved upscale
to the top stop position. The pen then moves back downscale to nominally place the pen at
the outer ring (100%) of the chart. The display will now display ArC. The pen arm may be
loosened and the length adjusted to a position and angle to place the pen tip near the outer
ring then re-tighten the pen arm. Press any key and the pen will drive to "HOME", then back
to the inner ring (0%) and PEnL will be displayed.
Zero and Span - To begin a pen zero, with PEnL in the display, the UP or DOWN key may be
pressed to move the pen to the low end of the chart span (0%). When adjusted, press the
SCROLL key and P uP is displayed while the pen is moved to the outer edge (100%) of the
chart, then PEnh is displayed. To adjust pen span, use the UP and DOWN keys to adjust the
pen for the high end (100%) of the chart. When adjusted, press the SCROLL key and P dn
will be displayed for about 5 seconds while the pen is moved to the 50% point on the chart,
then PEn1 is displayed. Calibration may now be performed again to verify the accuracy, or
press the UP key twice to exit back to the CAL mode.