Agilent Technologies 5975C TAD VL MSD Troubleshooting And Maintenance Manual page 188

6
Vacuum System
Table 10
Changes at
Function
Message
What it means
What to do
Check the condition and level of the diffusion pump fluid through the window
(sight glass) near the base of the front of the pump. See
drops below the appropriate marker (there are separate ranges for hot and
cold conditions) or if the fluid turns dark brown or black, replace the fluid.
Otherwise, replace the fluid once a year.
188
Diffusion pump thermal switches (continued)
5975 Series MSD Troubleshooting and Maintenance Manual
170 °C rising; 140 °C
falling
Keeps analyzer turned
off until the pump is hot
enough to for adequate
vacuum. Prevents
analyzer damage
The high vacuum pump
is not ready
Normal during
pumpdown
Wait for pump to heat up Check the level and
365 °C rising
Shuts off diffusion pump
and analyzer if the pump
overheats. Prevents
damage to the pump and
analyzer.
Difficulty with the high
vacuum pump
Always indicates a
problem
conditions of the fluid.
Make sure pump is cool,
and power-cycle MSD to
reset.
Figure 40. If the level