Pfeiffer Vacuum

1.2.7 pV flow

Dividing the general gas equation by time t yields the gas flow

Formula 1-11:

pV flow

This is also referred to as pV flow. As can be seen from the right-hand side of the equation, a constant mass flow is displaced at constant temperature T.

Vacuum pumps, particularly positive displacement pumps, have a constant volume flow rate of

Formula 1-12:

Definition of volume flow rate, or pumping speed

over a given inlet pressure range; i.e. they displace a constant volume flow. Multiplying the volume flow rate by the inlet pressure yields the throughput of a pump.

Formula 1-13:

Vacuum pump throughput

Throughput is the gas flow transported by a vacuum pump.

Table 1.6:  Conversion table for units of flow, length and temperaturezoom table
Table 1.6: Conversion table for units of flow, length and temperature

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