Recalibration - VWR Signature Ergonomic Manual De Instrucciones

VWR-EHP-180-07-2008 OK
The pipetting button should be depressed and released
slowly and evenly.
- When working with viscous samples, new tips must be
rewetted prior to pipetting, by drawing and expelling
the liquid to be measured.
- When pipetting liquids which tend to wet walls of tips,
such as serums, proteins, organic solvents, measuring
must be performed much more slowly than 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 pipettor should be stored vertically in
holder with tips removed.

5 - RECALIBRATION

VWR Signature ™ Pipettors are calibrated by a gravi-
metric method, using VWR tips and distilled water, at
the temperature 20±1°C, based on EN ISO 8655.
If during pipettor 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 pipettor recalibration
procedure should be carried out.
Before starting the recalibration procedure it is neces-
sary to check whether the following requirements have
been fulfilled during error determination:
• the ambient temperature, and the temperature of the
pipettor, tips and water was identical
• the density of the liquid used is close to that of dis-
tilled water
• the balance with appropriate sensitivity has been used
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 pipettor recalibration procedure
should be carried out.
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Balance sensitivity [mg]
≤ 0.001
≤ 0.01
≤ 0.1
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
pipettor, tips and liquid should be within the range
20-25°C and stabilized 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 pipettor volume
according to the following table:
Range
of the Preset
Model pipette volume
volumes [μl]
[μl]
VWR ME10
1 - 10 1
VWR MT10
VWR ME50
5 - 50 5
VWR MT50
VWR ME200
20 - 200 20
VWR MT200
VWR ME300
50 - 300 50
VWR MT300
• 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
water density coefficient [μl/mg], which depends on
temperature and pressure according to the following
table:
Temperature [°C]
20 1.0028
21 1.0030
22 1.0032
23 1.0034
24 1.0037
25 1.0039
ENGLISH
Volume change
Permissible
V 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
Pressure [kPa]
95.0 101.3 105.0
1.0029 1.0029
1.0031 1.0031
1.0033 1.0033
1.0035 1.0036
1.0038 1.0038
1.0040 1.0040
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