Internal Controls - Fluke Victoreen 190 Operator's Manual

3.8 Internal Controls

Display Contrast Adjustment (RP1)
The Model 190 display is designed for optimum viewing at approximately 60
and directed toward the bottom of the instrument. The Display Contrast Adjustment (RP1) is factory set
for optimum viewing and Fluke Biomedical does not recommend that it be further adjusted. However; if
the display contrast requires adjustment, turn RP1 to vary the angle of maximum contrast of the 16-
character display. The contrast for the upper part of the display is fixed. Refer to Figure 3-4 for RP1
location.
Voltage Adjustment (RP2)
A +5 volt adjustment is provided on the main circuit board. Refer to Figure 3-3 for adjustment location.
Use the following procedure:
1. Connect the - lead of a DVM to the groundside of R18.
2. Connect the + lead of the DVM to Z10-12.
3. Adjust RP2 for 5.00 volts +0.02 volts.
4
2
0
X0.0.0.010 MILLION
X0.100 THOUSAND
Figure 3-3.
Use extreme care and ensure that you are properly
grounded prior to opening the unit for voltage
adjustments. Failure to comply could destroy the
instrument.
6
8
10
Model 190 Display
CAUTION
Operation
Internal Controls
o
from the plane of the display
3
3-5