Edwards EXT200/200H GCMS, Инструкция по эксплуатации, Страница: 10 / 38

B756-01-880 Issue K
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Technical data
CAUTION
Do not use the EXT70/70/200H to pump gases containing more than 20% oxygen. If gases containing more than
20% oxygen are pumped, the pump lubricant will polymerise and the pump may fail prematurely.
Note: Concentrations of gases may be modified by the compression of the pump.
The pumps are designed to pump the following residual gases normally used in high-vacuum systems:
The pump can be used to pump oxygen and water vapour, subject to the following conditions:

Oxygen – The oxygen concentration must be less than 20% by volume.

Water vapour - Ensure that vapour does not condense inside the pump. Refer to Section 3.6.3 .
If there is a requirement to pump a gas not in the list above, contact the supplier for advice. If the supplier is not
contacted, the warranty on the pump may be invalidated. The pumps are not suitable for pumping aggressive or
corrosive gases.
2.3 Vent gas specification and vent control data
Although the pump may be vented to atmosphere, high relative humidity of the air may greatly increase the
subsequent pump-down time. To reduce pump-down times, vent the pump with dry, clean gases.
* If using pressures in excess of this figure, please consult Edwards.
WARNING
If pumping hazardous gases or vapours, the customer must observe the safety recommendations
of the supplier of the gas or vapour.

Air

Nitrogen

Helium

Carbon monoxide

Krypton

Hydrogen

Neon

Argon

Butane

Ethane

Propane

Methane

Carbon dioxide
Table 2 - Vent gas and vent control data
Vent gas Dry air, nitrogen, argon or other inert gases
Maximum dew point at atmospheric pressure -22 °C
Maximum size of particulate 1
µ
m
Maximum concentration of oil 0.1 parts per million
Time for rotational speed to reach 50% > 15 sec
Maximum vent gas pressure < 0.5 bar gauge (7 psig, 0.5x10
5
Pa gauge)*