Manual Pressure Control Packs
Connections
5
gmy02.bmp
Figure 2. Optional Setup for Positive Gauge Mode Only
gmy03.bmp
Figure 3. Optional Setup for Operation in Positive and Negative Gauge and Absolute Modes Using
One Vacuum Pump
3.
Reference Vacuum Pump isolation valve (such as part number 88-1038) is required
only for negative gauge mode operation. However, it is highly beneficial in the
absolute mode, especially when only one vacuum pump is used. The isolation valve
allows the bell jar to be vented to atmosphere (as when changing masses) without
deactivating the vacuum pump. Leaving the vacuum pump active allows the bell jar
to return to a stable vacuum more quickly. In the single vacuum pump absolute mode
configuration, the isolation valve allows the test port pressure to be decreased below
ambient pressure while the bell jar is vented.
