Thermo Scientific Dionex UltiMate 3000 Series Operating Instructions Manual page 204

UltiMate 3000 Series:
NCS-3500RS and NCP-3200RS
7.6.3.2 Cleaning the Pistons
Cleaning the pistons is required only if you reinstall the pistons you removed. Verify that the
pistons are clean and free of damage by using a light. Hold the rear side of the piston into the
light. Dirt particles will be enlarged by the refraction of the light.
Tip: Even if the piston seems to be clean, consider performing the fingernail test in
addition. Hold the piston and carefully move your fingernail over the surface.
After performing this test, you have to clean the piston again.
The piston is clean when the surface is completely smooth (no inconsistent or
rough areas).
1. Carefully rinse the piston (preferably with isopropanol), and then rub it several times
with a dry, lint-free tissue.
2. Consider repeating the fingernail test.
3. Inspect the piston for signs of damage. If no damage is visible, reinstall the piston. If
the piston is scratched or scored, install a new piston.
Page 196
Fig. 71: Fingernail test
Operating Instructions