User manual

Getting Started: Product Description
1–2
WFM 90 & WFM 91 User Manual
Description of Features
Rasterized Color LCD Display
The WFM 90 and WFM 91 uses a proprietary rasterizer which
displays analog waveforms or vectors on the color 4-inch diagonal,
backlit thin-film transistor (TFT) LCD raster display, simultaneously
with the appropriate measurement graticules. A viewing-angle
control for the display permits optimal signal viewing from different
positions.
The LCD display 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
the fading 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 is going to be
left alone for more than two hours.
Battery or AC Adapter Operation
The instrument can be powered by six C-cell batteries, (alkaline or
NiCad) by an internally rechargable NiCad battery pack, or by an AC
adapter wall unit with a negative center lead producing 12 VDC. The
rechargeable NiCad battery pack is automatically recharged when the
12 VDC adapter is plugged into the instrument, while instrument
power is on or off.
NOTE. To avoid uninterupted operation when using the wall adapter,
be sure that the batteries are installed in the instrument.