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2.25.3 Digital Vacuum Gauge for 2028 only
A digital vacuum gauge is incorporated into the model 2028 vacuum system.
The digital gauge is an absolute gauge located in the top front section of the Self-Cleaning system. The unit of
measurement is preset during production.
Set Units
- Allows the user to change vacuum units from torr, mbar, and kPa.
1) Press the MENU button on the front panel and use the vacuum control knob to scroll
to the “Setup” option # 3 and push in the Vacuum Control knob.
2) Scroll to “Set Units” option # 1 and push in the Vacuum Control knob.
3) Scroll to the desired units and push in the Vacuum Control knob. The * will appear
next to the selected and set units.
4) Push in the Vacuum Control knob to exit or scroll to “Back” to go back to the
previous screen.
5) The gauge will automatically display all values in the new unit of measurement.
2.26 Vacuum Level Regulation
Vacuum level regulation is accomplished with an adjustable bleed valve. The adjustable bleed valve allows close
control of pressure in your apparatus. Pressure may be set between roughly atmospheric pressure and the
maximum obtainable vacuum (2 torr, 2.7mbar, 29.8 in Hg).
2.27 Gas Ballast Valve (Models 2025, 2026 & 2027 only)
The gas ballast or vent switch acts to minimize vapor condensation when pumping heavy vapor loads.
In a pump functioning on an apparatus with a high vapor load, compression within the pump takes place in
the normal manner until the saturation pressure of gas and vapor is reached, causing the vapor to condense in the
pump mechanism. When air at atmospheric pressure is supplied to the compression stoke by means of the gas
ballast valve, the partial pressure of the unwanted vapor becomes a very small part of the total pressure of the
mixture of gas, vapor and newly supplied air. The vapor is then prevented from reaching its saturation pressure
corresponding to the temperature of the pump and is finally expelled from the pump as a vapor.
Models 2025, 2026 & 2027 have a toggle gas ballast valve incorporated in its design. By moving the
toggle switch to its upward position, the valve is opened. A fixed amount of air will then flow into the second
stage of the pump. Because of the increase in gas load, the pump’s ultimate pressure deteriorates slightly.
Prolonged operation of the pump with the gas ballast open is not injurious to the pump.
Vacuum Gauge
Separator
Outlet
Inlet
Vacuum Level
Regulator
Gas Ballast Valve
Purge
Light (Self-Cleaning)
Power Switch
(Model 2027 shown. Models 2025 and 2026 come with a dial vacuum gauge)
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