BRAND PLT unit Gebrauchsanleitung Seite 62

5 Performing the test
What does the vertical progress bar on the display show?
A
What if there are leaks?
If a dynamic test indicates the presence of leaks, you can attempt to localize the source with further
testing:
1.
A static test should be performed next.
The plunger button is not pressed; the piston is not moved.
If the instrument is now leak-tight, this may be an indication of any of the following:
Scratches on the piston
Defective piston seal
Use of unsuitable silicone grease
2.
The dynamic test should be performed without a tip.
Adapter 3 can be reused for this.
If the instrument is now leak-tight, possible causes may be any of the following:
Use of unsuitable tips
Defective tip cone
3.
If testing a multichannel pipette: Close three channels with the caps provided, and test the in-
dividual channels to localize the leak. Select the pipette type "Single Channel" for this!
When using pipettes with pistons lubricated with silicone grease, only use the grease recommended
by the manufacturer!
When using pipettes in which the pistons are operated without silicone grease, be sure not to lubri-
cate the pistons; otherwise, irreversible damage may result!
Please refer to the corresponding operating manual.
Note on duration of tests
In the first test after the device has been switched on, a relatively large volume must be pumped out,
after which the device must be given time to stabilize (relaxation). Regularly switching between large
and small pipette types leads to longer test durations because the measurement pressure must be re-
set each time.
The measurement time is generally 5 s for pipettes up to 500 μL and 10 s for 1250 µL pipettes.
62
Operating manual
B C
A mark is added to the progress bar. It indicates the thresh-
old value. It corresponds to approx. ¼ of the volume toler-
ance according to ISO 8655-2.
A: The progress bar is filled in all the way to the bottom: The
pipette is leak-tight.
B: The progress bar is filled in from the top only down to the
threshold value region: We recommend that a gravimetric
test be performed.
C: The progress bar is filled in to a point well above the
threshold value:
The pipette is leaky. A gravimetric test should be performed;
if necessary, the unit should be sent in for repair.
NOTICE
PLT unit 997960