Vacuum System; Overview - Agilent Technologies 5975C TAD VL MSD Troubleshooting And Maintenance Manual

6

Vacuum System

Overview

The vacuum system creates the high vacuum (low pressure) required for the
MSD to operate. Without the vacuum, the molecular mean free path would be
very short and ions would collide with air molecules before they could reach
the detector. peration at high pressures also would damage analyzer
components.
The 5975 Series MSDs use two vacuum pumps to obtain the vacuum levels
needed. One of two foreline pumps (standard or dry) creates a low vacuum,
then a high vacuum pump engages to create the vacuum needed for operation.
The 5975 Series MSD uses one of three kinds of high vacuum pumps: a
diffusion pump or one of two turbomolecular (turbo) pumps. The pump type
determines the maximum column flow supported by the MSD. See
Table 9
Model number
G3170A
G3175A
G3171A
G3176A
G3172A
G3174A
Most vacuum system operation is automated. Operator interaction is through
the data system or control panel. Monitor the vacuum system through the data
system and/or local control panel.
172
Recommended maximum flow rates per high vacuum pump
Description
Diffusion pump, EI
Standard turbo pump, EI
Performance turbo pump, EI
Performance turbo pump, EI, PCI, NCI
5975 Series MSD Troubleshooting and Maintenance Manual
Table
Maximum recommended
column flow
1.5 mL/min
2.0 mL/min
4.0 mL/min
4.0 mL/min
9.