Reservoir manostat

The action of the manostat may be explained with the aid of Fig. II, 23, 6. Mercury is introduced into the container until the disc of the float just makes contact with the oriflce, when the pressure is equalised inside and outside the float. The device is connected to the pump and to the system by way of a large reservoir and a manometer. With the stopcock open, the pressure in the system is reduced by way of a by-pass between the pump and the system until the desired value as read on the manometer is reached, then both the stopcock and by-pass are... 

In comparison to the usual ebulliometric equipment where the polymer solution is placed into the evaporator, only pure solvent is evaporated. The vapor flows through the cell and is condensed at its head-condenser to flow back into the reservoir at the bottom. The vapor pressure is kept constant using a manostat and is measured additionally outside the apparatus after the condenser. Equilibrium times decrease somewhat, degassing of the solvent is not necessary, air leakage does not play any role. 

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