The method of controlled evacuation

In this method evacuation of the apparatus takes place only when the pressure in the buffer vessel begins to exceed the required value. A pressure controller and relay can either start the pump or open a valve. A schematic diagram is shown in Fig. 374b. 

Gilmont s pressure regulator [40] operates on the principle of the Cartesian diver and can be used for pressures down to 6 mm. Fig. 376 shows this apparatus, mounted on a console together with a Stock manometer and a Friedrichs-Antlinger non-return valve [41], Its accuracy is about 0.5 torr. 

1 = racuiun pump, 2 = buffer vessel, 3 = manometer, 4 = pressure controller, 5 = electronic relay 

Pressure regulator with fritted glass disc 

Gilmont s pressure regulator (principle of the Cartesian diver) 

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