Pipetting Dense And Viscous Liquid - HTL CLINIPET+ Manual Del Usario

Volume checked [μl]
2 - 10
10 - 100
> 100
• the conversion factor mg/μl has been taken
into consideration in the calculations
• the requirements given in sections 2 and 4
have been fulfilled.
If you follow the instructions and the accuracy
error (A) still exceeds the permissible value carry
out the pipette recalibration procedure again.
Carry out recalibration procedure in the follow-
ing way:
• use distilled water for measurements
• obey the rule that ambient temperature and
the temperature of the pipette, tips and water
should be the same within the range 20-25°C
and stabilised during weighing within ± 0.5°C
• perform 5 aspirations, weigh each time using
the balance which meets the sensitivity re quir -
ements
• calculate the average value of the aspirations
• calculate the average aspirated volume, in μl,
multiplying the average aspiration amount in
[mg] by the distilled water density coefficient,
[mg/μl] which depends on temperature and
pressure according to the following table:
Density coefficient values for distilled water
Temperature [°C]
20
21
22
23
24
25
• determine the difference between the average
aspirated volume and the nominal volume of
the pipette.
If the difference does not exceed the permissi-
ble value of the accuracy error (A), the pipette is
set properly and does not require recalibration.
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Balance sensitivity [mg]
0.001
0.01
0.1
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
Otherwise:
• remove the pipette pushbutton, (Fig. 4A)
• insert the calibration key (with the smaller
diameter end) into the pipette opening, the
key should enter the calibration screw located
inside the pipette, (Fig. 4B)
• to reduce the aspiration volume turn the key
clockwise, to increase the aspiration volume
turn the key counter-clockwise, (Fig. 4C). One
full turn of the key corresponds to the change
of the aspirated volume of distilled water by
the amount V given in the table in section 1
- 24 increments
• take the calibration key out, fix the pipette
pushbutton and determine the average aspira-
tion amount again, (Fig. 1D)
• the determined volume should be within the
permissible range accuracy error (A)
• otherwise, repeat the recalibration procedure
once more.
More information on the recalibration procedure
can be found on www.htl.com.pl.

6 - PIPETTING DENSE AND VISCOUS LIQUID

The specification of accuracy and repeatability
of pipetting with CLINIPET + pipettes is based
on sampling distilled water. When pipetting
other liquids of different physical qualities like
density, viscosity and surface tension, it is rec-
ommended to aspirate and dispense that liquid
much slower.
When aspirating, the tip should be kept in the
pipetted liquid for at least 2 seconds. Similarly,
when liquid dispensing, you should wait a mini-
mum 2 seconds before you press the pipetting
pushbutton to its ultimate end.
If the difference between the real volume of
aspirated liquid and the nominal volume of the
pipette is considerable and inadmissible, the
pipette recalibraction procedure can be carried
out for the liquid actually aspirated.
Carry out the recalibration procedure as for dis-
tilled water by changing the liquid only.
ENGLISH
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