Recalibration - HTL discovery comfort DV8-10 Handbuch

• when pipetting, the DISCOVERY Comfort should have
the volume setting locked with the locking ring in the
upper position,
• do not draw liquids without tips fitted on the pipette
shafts,
• do not lay down the pipette with tips filled,
• do not draw volumes of liquid exceeding the pipette's
range,
• check if the tips are fitted properly,
• during operation, the pipette must be held vertically,
tips should be immersed in liquid to the depth of 2 to 4
milimeters and the pipetting button should be
depressed and released slowly and evenly,
• new tips must be rewetled prior to pipetting, by draw-
ing and expelling the liquid to be measured. This is
especially important when working with liquids of visco-
sities and densities different from that of water and
in temperatures different from ambient temperature,
• when pipeting liquids which tend to wet walls of tips,
such as serums, proteins or organic solvents, measuring
must be performed much slower then with other liquids,
• tips must be replaced with new ones, when changing
from one liquid to another, or if drops of liquid remain
inside the tips,
• after work, the pipette should be stored vertically in a
holder with tips removed.

5 - RECALIBRATION

HTL pipettes are calibrated by gravimetric method, using
HTL tips and distilled water, at the temperature 20±1°C,
according to EN ISO 8655 standard.
If during pipette operation you find that the accuracy
error (the difference between the real aspirated volume
and the preset volume) exceeds the permissible value
given in the table in section 1, the pipette recalibration
procedure should be carried out.
Before starting the recalibration it is necessary to check
whether the following requirements have been fulfilled
during error determination:
• the ambient temperature, and the temperature of the
pipette, tips and water was identical
• the density of the liquid used is close to that of distilled
water
• a balance with appropriate sensitivity has been used
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Volume checked [μl]
0.1 - 10
10 - 100
> 100
• mg/μl conversion factor has been taken into account
• the requirements given in sections 3 and 4 have been
fulfilled
If the above conditions are satisfied and the accuracy
error for selected volume given in section 1 exceeds the
permissible value, the pipette recalibration procedure
should be carried out.
The recalibration can be performed within one full turn
of the key to the right or to the left only.
Recalibration conditions:
• Ambient temperature and the temperature of the pi-
pette, tips and liquid should be within the range 20-25°C
and stabilised during weighing within ±0.5°C
• Measurements should be conducted using distilled
water
• Balance sensitivity should be suitable for the volume to
be controlled
Recalibration procedure:
• Set the dose volume depending on the pipette volume
according to the following table:
Range
of the Preset
Model pipette volume
volumes [μl]
[μl]
DV8-10
1 - 10 1
DV12-10
DV8-50
5 - 50 5
DV12-50
DV8-200
20 - 200 20
DV12-200
DV8-300
50 - 300 50
DV12-300
• Perform three aspiration series (each series should
include the aspirations from all channels), weigh each
time and calculate the average value of the aspirations.
• Calculate average aspirated volume in μl multiplying
the average aspiration amount [mg] by the distilled
ENGLISH
Balance sensitivity [mg]
≤ 0.001
≤ 0.01
≤ 0.1
Volume change
Permissible ΔV for full turn of
volumes the calibration
[μl] key [μl]
(24 increments)
0.92 - 1.08 0.33
4.8 - 5.2 1.67
19.4 - 20.6 6.30
49.2 - 50.8 10.00
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