Download 6 - Test Equipment Depot

Appendix B: User Service
Cleaning the Exterior
Clean the exterior surfaces of the instrument with a dry, lint-free
cloth or a soft-bristle brush. If dirt remains, use a cloth or swab
dampened with a 75% isopropyl alcohol solution. A swab is useful
for cleaning in narrow spaces around the controls and connectors. Do
not use abrasive compounds on any part of the instrument.
Interior
Interior cleaning and maintenance should be performed by qualified
service personnel only. Instructions for interior maintenance are
provided in the service manual.
Display
The LCD will retain an image if the instrument is left on in one
display mode for an extended period of time. This is typical for the
LCD display device. The retained image will fade over time, and
that time can be accelerated by leaving the instrument turned off.
CAUTION. LCD Display Image Retention
To prevent image retention in the LCD display, enable the backlight
time-out mode or turn the instrument off if the monitor will be left
alone for more than two hours.
Instrument Adjustment
The WFM90D and WFM91D can be adjusted entirely from the front
panel after entering the Calibration menu. The instrument should
only be adjusted by qualified personnel. The service manual contains
the instructions for adjusting the instrument.
B- 2
WFM90D and WFM91D User Manual