Checking The Volume (Calibration) - BRAND Dispensette S Trace Analysis Operating Manual

7 Checking the Volume (Calibration)

Depending on use, we recommend that gravimetric testing of the instrument be carried out every 3-12
months. This time frame should be adjusted to correspond with individual requirements. The com-
plete testing procedure (SOP) can be downloaded at www.brand.de.
For GLP- and ISO-compliant evaluations and documentation, we recommend the EASYCAL™ calibra-
tion software from BRAND. A demo version can be downloaded from www.brand.de.
Gravimetric volume testing according to DIN EN ISO 8655- 6 (for measurement conditions, see Error
limits, p. 46) is performed as follows:
1. Prepare the instrument
Clean the instrument (Cleaning, p. 49), fill it with distilled H
2. Check the volume
a.
10 dispensing operations with distilled H
mended
b.
For discharge, depress the piston slowly and steadily without force until the lower stop
c.
Wipe off the tip of discharge tube.
d.
Weigh the dispensed quantity on an analytical balance. (Please refer to the user manual of the
scale manufacturer.)
e.
Calculate the dispensed volume. The Z factor takes account of the temperature and air buoy-
ancy.
3. Calculation
x
i
Z
Coefficient of variation*
Standard deviation*
9974 91
O in 3 volume ranges (100 %, 50 %, 10 %) are recom-
2
= Weighing results
= Correction factor
(e.g. 1.0029 µl/mg at 20 °C, 1013 hPa)
–
x
Mean
–
Mean volume
V
Accuracy* A% =
V
0
CV% =
s =
O and then prime it carefully.
2
n
Number of weighings
=
∑ x
i
=
n
x – . z
=
–
–
V
V
0 . 100
V
0
Nominal volume
=
100 s
–
V
∑
x
( –
i
Z .
n – 1
7 Checking the Volume (Calibration)
–
2
x )
Operating manual
47