HP 7470A Operator's Manual page 35

Possible Cause
Pen Appears to Skip or Drag (Continued)
The plotting medium has oil
on the surface.
The plotting medium has a
watermark in it.
There is static buildup on pens
and plotting medium.
is
The pen fiber-tipped.
Variations in pen speed can
create variations in line width.
30
Skin oil, or other agents that
repel ink may be present on
the medium surf ace. Correct
the problem by using a new
sheet of medium. Keep hands
clean while working with the
medium, and always handle it
by the edges.
Some brands of media contain
a manufacturer's watermark.
Decrease pen speed to write
over the watermark.
In low humidity, static may
cause dust and particle build-
up, especially when plotting
on transparencies. To reduce
the problem, slow the pen
speed down, increase the
humidity in the plotting envi-
ronment, try another brand of
film that emphasizes static-
resistant qualities, or change
to another plotting medium.
Pen Tip Wears Out Quickly
The wear
broadening of the line. To
prolong fiber-tip pen life, use a
smooth plotting medium.
Line Width Is Not Uniform
Curves and characters are a
collection of many tiny line
segments. The plotter stops at
the beginning of each line seg-
ment that it draws, which
creates a bolder line on
shorter line segments than on
longer line segments. Lower-
ing the pen speed will make
the line width more uniform.
Solution
is
exhibited as a