Recalibration - VWR Signature EHP Manual Del Usuario

VWR EHP-03-2008 13 9-04-08
• Do not pipet liquids with temperatures above 70°C.
• When pipetting acids or corrosive solutions which emit
vapors, it is recommended to disassemble the shaft
and to rinse the piston and seal with distilled water after
finishing the pipetting operation.

8 - RECALIBRATION

The pipettor is calibrated by gravimetric method, using
VWR tips and distilled water, at the temperature 20±1°C,
based on EN ISO 8655 standard.
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 it is necessary 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 was close to that of distilled
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 7 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.
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 pipet-
tor, tips and liquid should be within the range 20-25°C
and stabilized during weighing within ± 0.5°C
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Balance sensitivity [mg]
0.001
0.01
0.1
• 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 Preset
Model of the pipette volume
volumes [μl] [μl]
VWR VE2/V2 0.1 - 2 0.2
VWR VE10/V10 0.5 - 10 0.5
VWR VE20/V20 2 - 20 2
VWR VE50/V50 5 - 50 5
VWR VE100/V100 10 - 100 10
VWR VE200/V200 20 - 200 20
VWR VE250/V250 50 - 250 50
VWR VE1000/V1000 100 - 1000 100
VWR VE5000/V5000 1000 - 5000 1000
VWR VE10000/V10000 1000 - 10000 1000
• Perform 5 aspirations, weigh each one 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
If the average aspirated volume exceeds the permissible
value, the following should be done:
Take off the pipetting pushbutton, (Fig. 4A).
Warning: The pipetting pushbutton consists of 2 parts:
the knob (Fig. 1A2) and the pushbutton (Fig. 1A1). After
removal of pushbutton, both parts are separated.
ENGLISH
Volume change V
Permissible
for full turn of the
volumes
calibration key [μl]
[μl]
(24 increments)
0.176 - 0.224 0.06
0.48 - 0.52 0.33
1.94 - 2.06 0.63
4.875 - 5.125 2.50
9.84 - 10.16 2.50
19.76 - 20.24 6.30
49.5 - 50.5 6.30
99.1 - 100.9 25.00
994 - 1006 125.00
975 - 1025 250.00
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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