Troubleshooting - HTL discovery comfort DV8-10 Handbuch

• Calculate average aspirated volume in μl multiplying
the average aspiration amount [mg] by the distilled
water density coefficient [μl/mg], which depends on
temperature and pressure according to the following
table:
Temperature [°C]
20
21
22
23
24
25
If the average aspirated volume exceeds the permissible
value, the following should be done:
• Remove the pipetting pushbutton, (Fig. 4A),
Warning: The pipetting pushbutton consists of 2 parts:
the knob (Fig. 1A2) and the pushbutton (Fig. 1A1). After
removal of the pushbutton, both parts are separated.
• Holding the volume setting knob to protect it against
rotation, insert the calibration key into the cuts of the
calibration screw, (Fig. 4B),
• Turn the key clockwise to reduce the aspirated volume,
or counter-clockwise to increase the volume, (Fig. 4C).
One full turn of the calibration key changes the pipette
aspiration volume by the amount given in the table.
• Take out the key and fix the pipetting pushbutton (Fig. 4D).
The pipetting pushbutton should be fixed by placing the
knob on the arbor first (Fig. 1A2) and then the pushbutton
(Fig. 1A1).
Determine the average aspirated volume. The average
volume should be within the permissible range given in
the table. If the volume exceeds the values stated, the
recalibration procedure should be repeated.
When pipetting liquids with physical properties conside-
rably different from those of water, follow the rules given
in section 5.
More information on calibration procedure can be found
on www.htl.com.pl
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Pressure [kPa]
95.0 101.3 105.0
1.0028 1.0029 1.0029
1.0030 1.0031 1.0031
1.0032 1.0033 1.0033
1.0034 1.0035 1.0036
1.0037 1.0038 1.0038
1.0039 1.0040 1.0040

9 - TROUBLESHOOTING

If you notice an improper pipette operation identify the
cause and eliminate the fault. To do this, follow the
instruction in the sequence provided. Replacement of
parts should be required only occasionally, and should
not occur under normal pipette use.
Droplets of liquid remain in the pipette tip.
• The tip is emptied too fast.
Decrease the speed of pressing the pipette push-
button.
• The tip wettability has increased due to extensive use.
Replace the tip with a new one.
Droplets of air appear in the liquid aspirated into the tip.
• The pipette tip immersion is too shallow.
Immerse the tip deeper according to the instructions.
• The pipette tip is incorrectly pressed onto the pipette
shaft.
Press the pipette firmly.
• The tip is damaged or worn out due to extensive use.
Replace the tip with a new one.
The pipette incorrectly aspirates the liquid or liquid
drops out from the tip.
• The pipette tip is incorrectly pressed onto the pipette
shaft.
Press the pipette tip firmly.
• The shaft nut is loose (Fig. 3F) in the models DV/D2-
DV/D1000
Tighten the shaft nut.
• The sealing surface of the shaft is cracked or scored.
Remove the tip ejector. Unscrew the shaft nut, inspect
the shaft and the piston assembly. Replace the dam-
aged parts (see Section 12). When reasembling the
pipette, the nut should be hand tightened.
In the models DV/D2, DV/D10 and DV/D20, the damage
of the shaft may also cause a damage of the piston
assembly. Replace the damaged parts (see Section 12).
When reasembling the pipette, the nut should be
hand tightened.
To remove the tip ejector in models DV/D5000 and
DV/D10000, remove the ejector pushbutton (Fig. 3N)
and using a screwdriver unscrew the tip ejector by
turning the screwdriver counter-clockwise.
ENGLISH
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