Calibration And Adjustment - Thermo Scientific Finnpipette FOCUS Instructions For Use Manual

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
Range Volume
µl
0,3-3 µl 3
0,3
0,5-5 µl 5
0,5
1-10 µl 10
1
3-30 µl 30
3
5-50 µl 50
5
10-100 µl 100
10
30-300 µl 300
30
100-1000 µl 1000
100
0,5-5 ml 5000
500
1-10 ml 10000
1000
readable graduation
0.00 1 mg
0.01 mg
0.1 mg
Inaccuracy
µl
±0.125
±0.125
±0.125
±0.125
±0.120
±0.120
±0.50
±0.50
±0.50
±0.50
±0.80
±0.80
±4.0
±4.0
±8.0
±8.0
±40.0
±40.0
±60.0
±60.0
Imprecision
% s.d.µl
±4.2 0.075
±42 0.075
±2.5 0.075
±25 0.075
±1.2 0.080
±12 0.080
±1.7 0.20
±17 0.20
±1.0 0.20
±10 0.20
±0.8 0.30
±8.0 0.30
±1.3 1.5
±13 1.5
±0.8 3.0
±8.0 3.0
±0.8 15.0
±8.0 15.0
±0.6 30.0
±6.0 30.0
7
cv%
2.5
25
1.5
15
0.8
8.0
0.7
6.7
0.4
4.0
0.3
3.0
0.5
5.0
0.3
3.0
0.3
3.0
0.3
3.0