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8. Remove the chart, chart plate and pen stop.
9. Mount a calibration chart onto the chart drive hub and lock in place. The calibration chart should be prepared by
cutting a chart into shape shown in figure 3d and gluing it to a stiffener of similar shape. This special chart will
allow calibration of the pens while permitting access to the recorder linkages when adjustments are necessary.
CAUTION: VERIFY THAT ALL LINKAGE IS FREE. ADJUST HORIZONTALADJUSTABLE LINK AND
DRIVE ARM AT PRECISELY THE SAME DISTANCE FROM BASE PLATE SO AS TO BE LEVEL.
SET THE RANGE ADJUST, PEN ZERO AND LINEARITY ADJUST SCREWS TO THEIR MIDPOINT.
10. Apply 50% differential pressure to the high pressure side and arrange the differential pressure linkage as shown in
figure 3d. Set a 90° angle between the drive arm and horizontal link, then by adjusting the length of the link, set a
90° angle between the pen arm and horizontal link. Set the differential pressure pen to 50% indicating position on
chart by adjusting zero adjust screw.
11. Release pressure and observe the pen. The pen should indicate zero. If the pen deviates less than 10% from zero
in either direction, perform fine adjustment by using the pen zero adjust screw and then proceed to step 11b. If the
pen deviates by more than 10% from zero, make adjustments as follows in step 11a:
a. Slacken the centre screw of the torque tube shaft whilst supporting the drive arm, slip the pen until it indicates
zero and re-tighten.
b. Apply 100% pressure and observe the pen. Make the necessary adjustment by slackening slightly the range
adjust locknut enough to slide the ratio post. If the pen is slightly over-ranged move the ratio post downward away
from the pen spindle and if the pen is under-ranged move the ratio post upward toward the pen spindle. Repeat
zero and 100% span adjustments until calibration at these two points is achieved.
c. Apply 50% pressure and observe the pen.
1. The pen should be on the 50% chart line.
2. If the pen is low, slacken the centre screw of the torque tube shaft whilst supporting the drive
arm,and move the pen up the chart to make a correction ten times as great in the high direction. Adjust
the pen to 50% by slackening the two clamp screws of the horizontal adjustable link and shortening its
length so the pen reads correctly.
3. If the pen is high,slacken the centre screw of the torque tube shaft whilst supporting the drive arm,and
move the pen down the chart to make a correction ten times as great in the low direction. Adjust the pen
to 50% by slackening the two clamp screws of the horizontal adjustable link and shortening its length so
the pen reads correctly. Make sure all linkage screws are re-tightened.
12. Repeat step 11 until all three points (0,50 and 100% indication) is achieved. To assure the accuracy of the unit a
nine point calibration check must be conducted at 1,24,50,74 and 100 % ascending and descending utilising the
chart lines for accuracy.
13. Replace the pen stop and set for 5% over-travel and prevent recorder pens from going off the recorder chart.
14. Unlock the chart drive hub and remove the temporary calibration chart.
15. Replace the chart plate by sliding it under the pens until it sits on top of the supporting pillars and engage each
retaining screw into the chart plate slots.
16. Replace the pen lifter. Place the pen lifter under the recording pens and secure by screwing it into the chart plate
whilst biased against the inner case wall.
17. Install the correct chart and engage hub to lock. Check pens have correct pressure to produce a continuous line.
Clearscan™ Recorder Series - Operating and Service Manual