Thermo Scientific Finnpipette F2 Instrucciones De Uso página 11

Finnpipette F2 Variable Volume Multichannel
Range Channels
1.0-10 µl 8, 12, 16
5-50 µl 8, 12, 16
10-100 µl 8, 12
30-300 µl 8, 12
Adjustment
Adjustment is done only for one volume. The recommended adjustment volume is the minimum
volume or 10% of the maximum volume. Multichannel pipettes adjustment check prior
calibration is done using one of the middle channels.
1. Place the service tool into the openings of the
calibration nut at the top of the handle.
2. Turn the service tool clockwise to increase, or
counterclockwise to decrease the volume.
3. After adjustment check the calibration according
to the instructions above.
Formulas for calculating results
Conversion of mass to volume
V = (w + e) x Z
Evaporation loss can be significant with low volumes. To determine mass loss, dispense water
to the weighing vessel, note the reading and start a stopwatch. See how much the reading
decreases during 30 seconds (e.g. 6 mg = 0.2 mg/s).
Compare this to the pipetting time from taring to reading. Typically pipetting time might be 10
seconds and the mass loss is 2 mg (10 s x 0.2 mg/s) in this example. If an evaporation trap or lid
on the vessel is used the correction of evaporation is usually unnecessary.
The factor Z is for converting the weight of the water to volume at test temperature and pressure.
A typical value is 1.0032 µl/mg at 22°C and 95 kPa. See the conversion table on page 63.
Inaccuracy (systematic error)
Inaccuracy is the difference between the dispensed volume and the selected volume of a pipette.
A = V - V
A =
0
V =
V =
0
Inaccuracy can be expressed as a relative value: A% = 100% x A / V
Imprecision (random error)
Imprecision refers to the repeatability of the pipettings. It is expressed as standard deviation (s)
or coefficient of variation (cv)
Standard deviation can be expressed as a relative value (CV)
CV = 100% x S / V
Volume Inaccuracy
µl µl
10 ±0,240
1 ±0,120
50 ±0,75
5 ±0,25
100 ±1,30
10 ±0,50
300 ±3,0
30 ±1,5
V = volume (µl)
w = weight (mg)
e = evaporation loss (mg)
Z = conversion factor for µl/mg conversion
inaccuracy
mean volume
nominal volume
s = standards deviation
v = mean volume
n = number of measurements
Imprecision Factory
% s.d. µl
±2,40 0,160
±12,00 0,080
±1,50 0,35
±5,00 0,10
±1,30 0,50
±5,00 0,20
±1,00 0,9
±5,00 0,6
0
11
cv% calibration tip
1,60 Flex 10
8,00
0,70 Flex 200
2,00
0,50 Flex 200
2,00
0,30 Flex 300
2,00
+