Matrix Impact2 - Recommendations for Accurate Pipetting

CALIBRATION
33
resets to factory setting (see Table D.1.2, Calibration
Specifications, for the factory calibration steps).
D.5 Recommendations for Accurate Pipetting
IMPACT and IMPACT
2
pipettors are factory calibrated to deliver
accurate volumes with distilled water at 20°C. By using the
calibration procedures described in Sections D.1, Calibrating the
IMPACT, and D.2, Calibrating the IMPACT
2
, you can pipet liquids
of different specific gravity with a high degree of accuracy and
reproducibility. For optimal pipetting results, refer to the following
recommendations:
n When using factory calibration, the liquid to be pipetted should
not contain specific gravity and vapor pressure that is
significantly different from distilled water.
n When pipetting liquids with low vapor pressure and/or high
surface tension, pre-wet the pipet tips with the liquid to reduce
possible loss of accuracy.
n Before aspirating any liquid, fully immerse pipet tips into the
liquid to prevent aspiration of air. Tips should be immersed
approximately ¼ inch (approx. 0.6 cm) below the liquid.
n When accurate dispensing of several increments of liquid are
needed, discard the last increment. The cumulative per-
centage of error from previous increments exists on the last
volume.
n Pipet viscous liquids at the slowest speed to ensure accurate
pipetting.
n During the dispensing of a liquid, touch the tip against the side
of the receiving container to prevent any liquid from remaining
on the tip.
n If you cannot touch the tip against the receiving container,
dispense the liquid at the fastest speed for crisp liquid
delivery.