Calibration And Adjustment - Thermo Scientific Finnpipette Focus Multichannel Plus Guide D'utilisation

3. Deliver the preset volume by gently depressing the push button to the first stop. Hold
the push button at the first stop. Some liquid will remain in the tip and this should not
be included in the delivery.
4. Continue pipetting by repeating steps 2 and 3.
Pipetting of heterogeneous samples
(deproteinization in blood glucose determination, for example)
Use steps 1 and 2 of the forward technique to fill the tip with sample.
Wipe the tip carefully with a dry clean tissue.
1. Immerse the tip into the reagent and depress
the push button to the first stop, making sure
the tip is well below the surface.
2. Release the push button slowly to the ready
position. This will fill the tip. Keep the tip in
the solution.
3. Depress the push button to the first stop and
release slowly. Keep repeating this procedure
until the interior wall of the tip is clear.
4. Finally, depress the push button all the way to the second stop to completely empty the tip.

Calibration and adjustment

All Finnpipettes are factory calibrated and adjusted to give the volumes as specified with
distilled or deionized water using the forward pipetting technique. It should be noted that
the use of other pipetting techniques may affect the calibration results. The pipettes are
constructed to permit re-adjustment for other pipetting techniques or liquids of different
temperature and viscosity.
Device requirements and test conditions
An analytical balance must be used. The scale graduation value of the balance should be
chosen according to the selected test volume of the pipette:
Volume range
under 10 μl
10-100 μl
above 100 μl
Test liquid: Water, distilled or deionized, "grade 3" water conforming ISO 3696. Tests are
done in a draft-free room at a constant (±0.5°C) temperature of water, pipette and air
between 15°C to 30°C.
The relative humidity must be above 50%. Especially with volumes under 50 μl the air
humidity should be as high as possible to reduce the effect of evaporation loss. Special
accessories, such as the evaporation trap, are recommended.
Procedure to check calibration
The pipette is checked with the maximum volume (nominal volume) and with the minimum
volume. A new tip is first pre-wetted 3-5 times and a series of ten pipettings is done with
both volumes. A pipette is always adjusted for delivery (Ex) of the selected volume. Use
of forward pipetting technique is recommended. The maximum permissible errors are
designed for forward method.
Procedure:
1. Do 10 pipettings with the minimum volume.
2. Do 10 pipettings with the maximum volume.
3. Calculate the inaccuracy (A) and imprecision (cv) of both series.
4. Compare the results to the limits in the Table 1.
If the calculated results are within the selected limits, the adjustment of the pipette is correct.
TABLE 1: Maximum permissible errors according ISO8655
readable graduation
0.00 1 mg
0.01 mg
0.1 mg
6
1 2 3 4 5