Hanna Instruments HI931, Руководство пользователя, Страница: 148 / 218

11-4
MAINTENANCE PERIPHERALS
11.1.4. ASSEMBLING THE BURETTE
To attach the dispensing tube and the aspiration tube, follow these steps:
• Insert the flat-shaped end of the titrant tubing into the valve outlet (A) and screw the fitting clock-wise to tighten. The highest of the 9 cuts
should be vertical in the final position.
• Bend the tube up into the vertical position to enter the highest cut of the fitting (C).
• Replace the tube lock fitting (D).
• Replace the blue tube protector (E) by sliding it over the clear titrant tubing, the protector will sit in the tube lock fitting.
11.1.5. 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
Auxiliary Functions
chapter).
• Insert the aspiration tube into cleaning solution, deionized water or titrant solvent.
• Prime burette to fill the burette (use 2 rinses) (see
Auxiliary Functions chapter).
• During second cycle remove the aspiration tube from the cleaning solution, deionized water or solvent 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:
• Remove the burette assembly from the pump.
• 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 burette removal tool.
• 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. Rinse with deionized water.
• Remove the excess liquid.
Warning : Avoid contacting the titrant with bare hands.
Avoid spilling titrant.
Clean the external side of the syringe and piston to remove aggressive chemicals.
Do not touch the white PTFE part of the piston or internal walls of the burette with bare hands or greasy materials.