Checking The Volume (Calibration) - BRAND Dispensette S Mode D'emploi

V
N
. A
A
=
T
V
T
e.g.
V
N
V = 50% N
T
V = 10% N
T
*A = Accuracy, CV = Coefficient of Variation
The error limits in DIN EN ISO 8655-5 are significantly lower. The maximum error for a single mea-
surement can be approximated from the sum of error limits EL = A + 2 × CV (for 25 ml: 125 µl + 2 x 25
µl = 175 µl).

8 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. In addition, you can also perform
a function test at shorter intervals, e.g. dispensing the nominal volume into a volumetric test flask
(volumetric flask with 3 marks, DAkkS calibrated).
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. 52) is performed as follows:
1. Preparation of the instrument
Clean the instrument (Cleaning, p. 56), fill it with distilled H
2. Check the volume
a.
10 dispensing operations with distilled H
mended.
b.
For filling, pull up the piston gently until the upper stop of the volume set.
c.
For discharge, depress piston slowly and steadily without force until the lower stop.
d.
Wipe off the tip of discharge tube.
e.
Weigh the dispensed quantity on an analytical balance. (Please follow the operating manual of the
balance manufacturer.)
f.
Calculate the dispensed volume. The Z factor takes account of the temperature and air buoyancy.
9974 90
Partial volumes
The percentage values for A and CV are relative to the nomi-
N
nal volume (V
(V ).
p
Volume
A* ≤ ± %
25.0 0.5
12.5 1.0
2.5 5.0
NOTICE
O in 3 volume ranges (100 %, 50 %, 10 %) are recom-
2
8 Checking the Volume (Calibration)
) and must be converted for partial volumes
N
μl
CV* ≤
125 0.1
125 0.2
125 1.0
O and then prime it carefully.
2
μl
%
25
25
25
Operating manual
53