Varian 990 dCLD II, Operation Manual

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Model 990 dCLD II Component Leak Detector
4-16
MANUAL RANGE To read out one fixed decade, touch the MANUAL RANGE ON/
OFF toggle box to display
ON and then set the value of the decade
in the MANUAL RANGE box. This value must be set between the
values of the TOP and STOP Range; other values are rejected.
Auto-Ranging
ENABLED
When MANUAL RANGE is set to OFF , Auto-Ranging is enabled.
The system reads out a maximum four decades starting from the
value set for the TOP RANGE parameter. If RANGE STOP is ON,
the system measures
from the TOP RANGE decade to the RANGE
STOP decade.
RANGE STOP When Auto-Ranging is enabled (MANUAL RANGE is set to OFF),
you can limit the range to less than four decades. Touch the
RANGE STOP ON/OFF toggle box to display
ON and then set the
decade in the RANGE STOP box. The system then measures from
the TOP RANGE decade to the RANGE STOP decade.
TOP RANGE Set the TOP RANGE to the least sensitive value the configured sys-
tem will evaluate. See Table 3-1 on page 3-6 and “TOP RANGE”
on page 3-8 for a discussion of how to determine this value.
4.6.4.1 Leak Rate Range Selection through Turbo Speed Set-Up
The 990 dCLD II electronics allow for the display of only four full decades of sensitivity at
one time. The four decades displayed depend on the pump model being used in conjunc-
tion with the TURBO SPEED and TOP RANGE selection set by the user.
Touch the TURBO SPEED FAST/SLOW toggle box to switch between SLOW and FAST. The
mode displayed indicates the current speed of the turbo.
4.6.5 Output Control Setup
Touch the OUTPUT CONTROL SET-UP box to display the Output Control Set-Up screen
(Figure 4-14). From here, select the desired leak rate output and type of bar graph display.
Figure 4-14 Output Control Set-Up Screen
BACK
LEAK RATE
OUTPUT
CAL
LEAK
SET-UP
REJECT &
AUDIO SET
POINTS
RANGING
SET-UP
CONTROL
SET-UP
TO
SERVICE
MENU
ZEROING
SCREEN UNITS
SET-UP
OUTPUT CONTROL SET-UP
BACK
1V/DEC
LOG
OUTPUT
LINEAR
BAR GRAPH
DISPLAY