Advanced Instruments OsmoTECH XT - Page 75

Chapter 8 Maintenance and troubleshooting
76
OsmoTECH XT Single-Sample Micro-Osmometer User Guide
To replace the sampler plunger wire:
1. Unscrew the calibration gauge and key.
2. Rotate the sampler shaft until the calibration setscrew
appears beneath the access hole in the side of the
sampler body.
3. Place the key end of the calibration gauge in the
access hole and turn counter-clockwise to loosen the
setscrew.
4. Carefully remove the old sampler plunger wire.
5. Place a sampler tip on the sampler to help you place
new wire correctly.
6. Slip the sampler plunger wire into the sampler tip so
the Teflon plunger tip protrudes about 1/16" or 1.6mm
from the end of the sampler tip.
NOTE: If the sampler plunger wire cannot be placed
into the sampler tip without using excessive
force, follow the instructions under Fixing a
too-tight fit.
7. Using the key end of the calibration gauge, push the
sampler plunger wire into the sampler as far as it will
go.
8. Tighten the calibration set-screw with the calibration
gauge.
9. Screw the calibration gauge and key back into the top
of the sampler.
Your 20-μL sampler is now calibrated and ready to use.
NOTE: For best results, follow the instructions under
Verifying the sampler calibration to confirm that
the sampler is calibrated correctly.
Fixing a too-tight fit
1. Place the wire end into the back end (large diameter)
of the sampler tip.
Sampler tip
Sampler
plunger
wire tip
2. Install the sampler plunger wire and tighten.
3. Move the sampler tip in a back-and-forth motion over
the plunger wire and tip until the fit is acceptable.
4. Remove both parts and re-assemble normally.
Verifying the sampler calibration
Perform this verification procedure after you replace the
sampler plunger wire, or any time you want to confirm
that the sampler is calibrated correctly.
1. Place a new sampler tip on the sampler.
2. Unscrew the calibration gauge and key.
3. Insert the key end of the calibration gauge into the
sampler tip.
4. Visually inspect the position of the end of the sampler
plunger wire tip and the end of the calibration key.
NOTE: There should be no gap between the two.
5. If necessary, reset the sampler plunger wire as
described above.