Eppendorf Research plus - Manual (Page 22)

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Eppendorf Research® plus — Operating manual
5.5 Adjusting pipettes
5.5.1 General notes on user and factory adjustment settings
The Research plus was adjusted, tested and fitted with a gray adjustment seal with the
abbreviation "ADJ" before delivery. The adjustment display on the side reads "0".
Changing the adjustment of the Research plus is sometimes recommended for solutions which
are very different from water with regard to their density, viscosity, surface tension and/or vapor
pressure etc. If the density of an aqueous solution changes by approximately ±10%, for example
because of the salt concentration, the volume changes by approximately ±0.2%. This statement
does not apply if other relevant properties of the liquid also change.
If the pipette is used at extremely high altitudes, it must be calibrated to the ambient air pressure.
At 1 000 m above sea level, the volume error of a 100 μL pipette is about –0.3%.
When using special tips, that is, tips that significantly differ from standard tips in their geometry,
changing the adjustment can improve the dispensing accuracy (systematic error). The CD
Research plus contains adjustment tips for epT.I.P.S. long.
Adjustment changes can be reset by simple steps.
In addition to changing the user adjustment, a Research plus with variable volume setting can be
permanently changed by altering the factory adjustment (see Changing the factory adjustment
on p. 25).
Changes made to the user or factory adjustment do not affect dispensing precision (random
error). Precision can be improved by exchanging worn parts. Precision is also considerably
affected by handling.
Before changing the adjustment or factory calibration, you must check the existing dispensing
volume.
The actual volume can be checked by weighing:
NOTICE!
NOTICE! Incorrect dispensing volume for special liquids and from temperature
differences.
Solutions which differ greatly from water in terms of their physical data, or temperature
differences between the pipette, pipette tip and liquid can result in incorrect dispensing
volumes.
 Avoid temperature differences between pipette, pipette tip and liquid.
 Make sure that the temperature is constant, between 20 and 25°C and at ±0.5°C.
 Check the dispensing volume and readjust the pipette in case of deviations.
Hint!
The systematic and random errors recorded on delivery can be found in the Certificate
of Conformity. This certificate is included in the delivery. Changes to the factory
adjustment will render the certificate void.
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