Pipetting Liquids Of Varying Density; Temperature Considerations; Acids And Corrosives - OHAUS ACROSS PRO AO-2 Manual Del Usuario

Pipetting Liquids of Varying Density

let's you compensate for solutions of density much different
ACROSS P
RO
from water, by setting the volume slightly higher or lower than that required.
The compensation amount must be determined empirically.
E.g., if pipetting 10μl of CsCl solution, you determine that the volume
delivered is actually 8.5 μl (average of 5 samples). Try increasing the
volume setting to 11.8μl and repeat the measurements. If the volumes
delivered are still not close enough to 10μl, make another slight volume
adjustment until the measurements are as desired.
Very dense liquids may not be suitable for air displacement pipetting.

Temperature Considerations

Warm or cold liquids can be measured with good precision by using a
consistent pipetting rhythm. This will help minimize any differences in
heating or cooling effects within the pipette. Use a new tip each time for
best accuracy and precision when measure samples with temperatures
greatly different from ambient, and do not pre-rinse. You will get best
results if there is no delay between picking up the
sample and dispensing it.
If working in a cold room, allow the pipette to stabilize at ambient
temperature before operation.

Acids and Corrosives

After pipetting concentrated acids or highly corrosive solutions, you should
disassemble, inspect and clean (if necessary) the piston, shaft, and seal
assemblies.
Extensive contact with corrosive fumes may corrode the piston. This will
result in premature seal wear and may require refinishing or replacement of
the piston. Exposure of internal components to corrosive fumes can be
reduced by using aerosol-resistant tips. These tips have an internal filter
which acts as an aerosol barrier.
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