[Boatanchors] Meter window care

[telegrapher at att.net]

I found this text in a manual and thought it might be of assistance to 
some members of the community.


Meter Window Care

A clear acrylic meter window can become susceptible to 
electrostatic-charge buildup and can be scratched, if improperly cleaned.

It is treated inside and out in manufacturing with a
special non-abrasive anti-static solution. Statnul or any
other antistatic application, which normally should preclude
any interference in meter operation caused by
electrostatic effects. The problem is evidenced by the
inability of the meter movement to return promptly to
a zero reading, once it is deenergized. As supplied the meter
should return to zero reading within 30 seconds, immediately following 
the placement of a static charge, as by rubbing the outside
surface. This meets the requirements of ANSI standard C39.1-1972.

If static-charge problems occur, possibly as the result
of frequent cleaning, the window should be carefully
polished with a soft dry cloth, such as cheesecloth or
nylon chiffon.  Then, a coating of Statnul should be applied with the
polishing cloth.

CAUTION

Do not use any kind of solvent. Kleenex or paper
towels can scratch the window surface.
If it should be necessary to place limit marks on the
meter window, paper-based masking tape is recommended,
rather than any kind of marking pen, which
could be abrasive or react chemically with the acrylic.