Metrohm 700 Dosino - Manual (Page 40)

3. The Dosino in practice
700 Dosino, Instructions for Use
34
Dosing unit leaks from distributor
Possible cause:
• Leaky distributor disk.
⇒ Clean the stopcock washer and distributor disk, see page 29.
Liquid above the piston
Possible cause:
• Worn or faulty piston and/or cylinder.
⇒ Replace dosing piston and cylinder, see page 13.
Liquid drips into the bottle
Possible cause:
• Air in the cylinder.
⇒ Check the tubing ends, in particular that of the aspiration tub-
ing.
⇒ Tighten all tubing connections manually.
⇒ Check whether the housing is properly locked. If necessary
remove the housing and then put it back on again.
• The reagent releases a lot of gas, i.e. dissolved air forms
bubbles.
⇒ Carry out PREP.
⇒ Lower the filling speed.
⇒ If necessary degas the reagent, i. e. with helium, vacuum or
an ultrasonic bath.
• Wear and tear.
⇒ Replace piston and/or cylinder.
• PREP not carried out or incorrect parameters.
⇒ Carry out PREP.
⇒ Correct tubing lengths and diameters.
Dosing unit is not recognized or incorrectly recognized
Possible cause:
• Dosing drive not attached correctly.
⇒ Check whether the nominal volume on the dosing unit housing
is correct.
⇒ Remove Dosino and put it back on again.
⇒ Check whether the drive is correctly seated.
⇒ Switch control instrument off and on again.
⇒ If necessary contact your local Metrohm service center.