Hanna Instruments HI 903 - Manual (Page 121)

8-5
MAINTENANCE, PERIPHERALS
8.1.5 Cleaning the Burette
To clean the burette, follow these steps:
• If the burette is filled with titrant, remove the aspiration tube from the titrant bottle
and purge burette ( see Section 7.2.4, Purge Burette ).
• Insert the aspiration tube into the Karl Fischer solvent.
• Prime burette to fill the burette with solvent (use 2 rinses) ( see Section 7.2.1, Prime
Burette ).
• During second refilling of the burette remove the aspiration tube from the solvent or
cleaning solution and allow the air to replace the liquid in the burette. This will clean
the aspiration tube.
If this simple cleaning procedure is not adequate, continue with these steps:
• Slide the burette out from the pump assembly.
• Remove the dispensing and aspiration tubes. Clean them separately or insert new
ones.
• Remove the protective cap from the bottom of the burette assembly by using the
special tool (HI 900942).
• Remove the syringe from the burette assembly by unscrewing it with your fingers.
• Extract the piston from the syringe.
• Clean both the piston and the syringe with appropriate cleaning solution.
• Remove the excess liquid.