Eppendorf Research plus - Manual (Page 23)

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Eppendorf Research® plus — Operating manual
The density of distilled water is approx. 0.9982 mg/μL at 20°C and 0.9965 mg/μL at 27°C.
If the set volume corresponds to the actual volume, no correction is necessary.
If there is a difference between the actual volume and the set volume of distilled water, please
check the following:
•
Is there any liquid dripping from the tip?
•
Is the pipette tip fitted leak-proof?
•
Is the tip cone undamaged?
•
Are the piston and the cylinder leak-proof?
Adequate leak tightness is ensured when no drop is formed at the pipette tip after aspiration
of the nominal volume with distilled water and a waiting time of approx. 15 s. Hold the pipette
vertically, making sure not to touch the pipette tip. Prewet the tip several times in the case of
nominal volumes ≤ 20 μL.
•
Does the temperature of the pipetted liquid correspond to:
– the temperature of the device?
– the ambient air temperature?
•
Is the weighing location free from drafts?
•
Does the work method and pipetting speed permit complete aspiration and dispensing of the
liquid?
•
Has the correct numerical value for "Density liquids at weighing temperature" been used for
the calculation of the actual volume?
•
Is the set volume correct?
•
For very small volumes (<10 μL): is the fine balance sufficiently sensitive (balance resolution:
0.001 mg)?
•
Were original epT.I.P.S pipette tips used for testing?
Information as to which pipette tip must be used as a test tip for checking the technical data
can be found in the "Technical Data" chapter of the operating manual.
No adjustment changes are allowed unless you can answer all the questions with "yes". In all
other cases, the problems associated with the questions answered with "no" must be eliminated.
If the problem is remedied by exchanging a complete lower part or other parts that have an effect
on the volume, proper assembly must be verified by carrying out a gravimetric test. Information
on the systematic and random errors to be met can be found in the "Technical Data" chapter.
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