Checking The Volume - LABBOX EASY 20K Manual Del Usuario

Note:
rapid cooling. After every autoclaving, inspect all parts for deformities or damage. If
necessary, replace them. Do not reassemble the instrument until it has cooled down to
room temperature (cooling time approx. 2 hours).
Mounting tool can be steam sterilized at 121 °C.

12. Checking the volume

The accuracy and coefficient of variation of the instrument are determined gravimetrically as follows:
- Set to the nominal volume.
- Dispense distilled H O.
2
-
Weigh the dispensed quantity on an analytical balance.
-
Calculate the dispensed volume taking the temperature into account.
-
Perform at least 10 dispensing and weighing operations.
- Calculate the accuracy (A%) and the coefficient of variation (CV%) by means of the formular used in statistical
quality control. The proceeding is described e.g., in DIN EN ISO 8655-6. Observe the operating manual of the
balance manufacturer and the corresponding standards.
13. Calculations (for the nominal volume)
Mean value
Mean volume
Z= correction factor
_
Accuracy
V nominal volume
0=
Coefficient of variation
Allow to cool down in the closed autoclave to avoid deformation through too
x
n= number of weighings
Standard deviation
results of weighings
i=
10