Sartorius BIOHIT Picus User Manual

23
4.3 Performance testing
It is recommended that the performance of your Sartorius Biohit pipettes
is checked regularly (e.g. every 3 months) and always after in-house
maintenance. A regular testing routine should be established by the users for
their pipettes having regard to the accuracy requirements of the application,
frequency of use, number of operators using the pipette, nature of the liquid
dispensed and the acceptable maximum permissible errors established by the
user (ISO 8655-1).
Performance tests should take place in a draught-free room at 15–30°C,
constant to ±0.5°C and relative humidity above 50%. The pipette, tips and
the test water should have stood in the test room for long enough (at least
2 hours) to reach equilibrium with the room conditions. Use distilled or de-
ionised water (ISO 3696, grade 3). Use an analytical balance with a readability
according ISO 8655-6.
Weighting
1. Adjust the desired test volume V
S
2. Carefully fit the tip onto the tip cone.
3. Fill the tip with test water and expel to waste five times to reach
humidity equillibrium in the dead air volume
4. Replace the tip. Pre-wet the tip by filling it once with the test water and
expell to waste.
5. Aspirate the test water, immersing the tip only 2-3 mm below the surface
of the water. Keep the pipette vertical.
6. Withdraw the pipette vertically and touch the tip against the side wall of
the test water container
7. Pipette the water into the weighting vessel, touching the tip against
the inside wall of the vessel just above the liquid surface at the angle of
30° to 45°. Withdraw the pipette by drawing one tip 8-10 mm along the
inner wall of the weighing vessel.
8. Read the weight in mgs (m
i
).
9. Repeat the tet cycle until 10 measurements have been recorded.
10. Convert the recorded masses (m
i
) to volumes (v
i
) by multiplying the mass
with the correction factor Z (Z-values in the table below): V
i
= m
i
Z
11. Calculatethemeanvolume(V)delivered:V=(ΣVi)/10
12. For conformity evaluation calculate the systematic error es of the
measurement:
in μl: e
S
= V – V
S
V
S
=selected test volume
or in %: e
S
= 100 (V – V
S
)/V
S
13. For conformity evaluation calculate the the random error of the
measurement:
as standard deviation:
or as coefficient of variation CV=100s/V
14. Compare the systematic error (inaccuracy) and random error
(imprecision) to the performance specification values of your own
laboratory.

Sartorius BIOHIT Picus Specifications

General

Brand	Sartorius
Model	BIOHIT Picus
Category	Laboratory Equipment
Language	English