202
5
Vacuum System
Turbomolecular pump and fan
Turbomolecular pump and fan
The 250 liters/second turbomolecular (turbo) pump creates the low pressure
(high vacuum) required for correct analyzer operation. The turbo pump in the
MSD is clamped directly to the bottom of the vacuum manifold.
The turbo pump has a cylindrical body with its inlet open to the interior of the vac-
uum manifold. Inside the pump body is a central shaft or cylinder. Sets of small
blades (airfoils) radiate from the central shaft, which spins at up to 60,000 revolu-
tions per minute.
The turbo pump transports gas by momentum transfer. The turbine blades are
angled so that when they strike a gas molecule it is deflected downward. Each set
of blades pushes the gas molecules further down toward the pump outlet. The
foreline pump is connected by a hose to the outlet of the turbo pump. It removes
the gas molecules that reach the outlet.
A separate controller regulates current to the pump and monitors pump motor
speed and temperature. A cooling fan is located between the turbo pump and the
front panel of the MSD. The fan draws air from outside the MSD and blows it over
the pump.
The turbo pump turns on automatically as soon as the MSD power is switched on.
The system will allow the analyzer to be turned on when the turbo pump is greater
than 80% speed, but the pump normally operates at 100% speed. The turbo pump
typically maintains an indicated pressure below 7 x 10
-5
Torr for GC carrier gas
flows up to 4 ml/minute. Pressure (vacuum) can only be measured if your MSD is
equipped with the optional gauge controller.
The turbo pump spins up (starts) and spins down (stops) quickly. This simplifies
pumpdown and venting. From initial power-on, the system can pump down to
operating pressure in 5 to 10 minutes.
The MSD ChemStation has pumpdown and venting programs to guide you through
these procedures. Follow their instructions carefully.
See Also
Gauge controller
, page 208
To pump down the MSD
, page 58
To vent the MSD
, page 52
Table 2. Typical MSD pressure readings for various carrier gas flow rates,
page
Содержание 5973
Страница 1: ...H Hardware Manual HP 5973 Mass Selective Detector ...
Страница 3: ...HP 5973 Mass Selective Detector Hardware Manual ...
Страница 25: ...1 Installing GC Columns To condition a capillary column 25 ...
Страница 30: ...30 ...
Страница 37: ...2 Operating the MSD To view MSD analyzer temperature and vacuum status 37 ...
Страница 39: ...2 Operating the MSD To set monitors for MSD temperature and vacuum status 39 ...
Страница 41: ...2 Operating the MSD To set the MSD analyzer temperatures 41 ...
Страница 43: ...2 Operating the MSD To set the interface temperature from the ChemStation 43 ...
Страница 51: ...2 Operating the MSD To remove the MSD covers 51 Upper cover Lower cover ...
Страница 92: ...92 ...
Страница 103: ...4 Maintaining the MSD To check and add foreline pump oil 103 Lower line Oil level window Fill cap Upper line ...
Страница 105: ...4 Maintaining the MSD To drain the foreline pump 105 Fill cap Drain plug Pump motor ...
Страница 107: ...4 Maintaining the MSD To refill the foreline pump 107 Fill cap Upper line Oil level window Drain plug ...
Страница 109: ...4 Maintaining the MSD To replace the oil trap 109 Oil trap Clamp O ring assembly Oil trap adapter Foreline pump ...
Страница 111: ...4 Maintaining the MSD To check the diffusion pump fluid 111 Fan Fluid level window sight glass ...
Страница 113: ...4 Maintaining the MSD To separate the MSD from the GC 113 ...
Страница 121: ...4 Maintaining the MSD To reconnect the MSD to the GC 121 ...
Страница 123: ...4 Maintaining the MSD To remove the calibration vial 123 Calibration valve Collar Calibration vial ...
Страница 125: ...4 Maintaining the MSD To refill and reinstall the calibration vial 125 Calibration valve Collar Calibration vial 6 mm ...
Страница 141: ...4 Maintaining the MSD To lubricate the side plate O ring 141 Side plate O ring ...
Страница 159: ...4 Maintaining the MSD To remove a filament 159 Filament 2 Filament 1 ...
Страница 161: ...4 Maintaining the MSD To reinstall a filament 161 Filament 2 Filament 1 ...
Страница 210: ...210 ...
Страница 211: ...6 GC MSD Interface This chapter describes the function of the GC MSD interface GC MSD interface 212 ...
Страница 214: ...214 ...
Страница 232: ...232 7 Analyzer Analyzer heaters and radiators ...
Страница 280: ...280 ...
Страница 294: ...294 Index ...
Страница 296: ...294 Chapter ...
Страница 297: ...H Manual Part Number G1099 90027 Copyright 1998 Hewlett Packard Printed in USA 11 98 ...