Sample Eject (Lift) Problems
NMR Case
Trouble Shooting Guide
BRUKER
Page 4 of 15
1. Sample Eject (Lift) Problems
1.1
Sample lift air flow
When ejecting the sample, it must come up with speed (within 10 seconds) and climb all the way to the top of the NMR Case.
There must be enough airflow so that the top of the spinner is pressed against the sample stop head on top of the sample tray.
If the sample creeps up very slowly and barely reaches the sample stop, then the sample lift airflow must be increased. There
is a dedicated method on how to adjust the sample lift airflow within the NMR console. It is done either by software or with
the BSMS. Do not increase the console main air pressure. Read the corresponding manual on how to adjust the sample lift
airflow (or ask Bruker for assistance).
In case the sample lift airflow needs to be increased fully to its maximum, then there is possible an air leak. Read and follow
sections 1.3 to 1.8 to find the fault.
1.2
Sample holder tray slamming
If the sample holder tray slams when advancing, it may need more sample lift air than necessary. See section 5 for
adjustments.
1.3
Light barrier
There is a light barrier built into the top part of the BST shim stack, It slows down the sample lift. Use the sample control
modifier cable P/N B1428 to disengage the light barrier. Read the instruction sheet P/N B2300.
1.4
Seals
To avoid sample lift air leaks, the following four seals must be properly installed (see installation manual Figure 1, page 17):
1.
Inside the adapter collar: one O-Ring.
2.
On top of the adapter collar: one flat rubber seal.
3.
Inside the large white round ring plate: one flat rubber seal.
4.
One white or brown seal ring on top of the large white round ring plate.
1.5
Seating of the adapter collar
Check that the adapter collar is seated correctly on top of the BST shim stack. The lower end of the collar must be flush with
the lower end of the top large portion of the BST.
1.6
Alignment of the adapter collar, seal ring and brown interface tube.
The adapter collar, seal ring and brown interface tube inside the collar must be aligned. Loosen the three screws of the collar
and insert the gray safety ring through the seal ring into the brown interface tube. The safety ring serves as alignment tool.
Tighten the three screws again and remove the safety ring.
1.7
Sample lift air bypass
There is a small pneumatic cylinder located inside aluminum housing underneath the NMR Case base plate (see Figure 2 and
Figure 3). This cylinder opens and closes a sample lift air bypass exit hole, located in the adapter collar. Check for the correct
closing of this bypass exit hole.
If the bypass exit hole is not closed completely, the sample will not eject to the top of the sample tray, but will sit on top of
the BST instead.
