Dwyer LCR20 - Manual (Page 11)

April, 2003 Page 11 of 20 LCR20 IOM
2-11 Changing the Chart
Press and release the CHANGE CHART button (#3), Figure 3-1 (pg. 14).
The pens will move to the left of the chart and the LED begins blinking
rapidly. Unscrew (counterclockwise) the chart “hub” knob at the center of
the chart. Wait until the pens stop above outer ring AND the green LED
goes to on steady.
Remove the old chart paper and position the new one so that the correct
time line coincides with the time line groove on the left side of the chart
plate.
Refer to Figure 2-5 (pg. 13) for the location of the time line groove.
Re-attach the chart “hub” knob and screw securely (by hand) against the
chart. Press and release the CHANGE CHART button (#3). The pens will
move to the outer ring and then pause. The LED remains on.
The pens will move to the current input values. Check to make sure that
the pens are marking on the chart paper. If not, then carefully adjust the
pen arm to establish contact with the paper.
2-12 Chart Pens
The chart pen consists of a self contained ink reservoir with a porous
plastic stylus which is fastened around the outer edge of the metal pen
arm.
A pen cap is provided to extend the life of the ink pen during shipping or
when the recorder is not in service. To remove the pen cap, gently lift the
pen arm away from the chart paper. Remove the black plastic pen cap to
expose the fi ber tip of the ink pen and gently place the pen back onto the
chart paper. Do not let the pen arm “snap” back onto the chart paper. This
will fl atten the fi ber tip of the pen and will no longer give you a fi ne line
marking on the chart paper. Place the pen cap in a safe place for future
use.
If the stylus does not touch the chart, adjustment can be made by slightly
bending the metal pen arm in the center towards the chart paper. Do
not use more pressure than is necessary to create a fi ne line marking on
the chart paper. Note: As the pen ink supply runs out, the pen color will
become lighter. This indicates that the pen should be replaced.