Error limits, English, 20 °c ex – BrandTech Scientific Titrette User Manual
Page 45
English
45
Error Limits
Error limits related to the nominal capacity (= maximum volume) indicated on
the instrument, obtained when instrument and distilled water are equilibrated
at ambient temperature (20 °C/68 °F). Testing takes place according DIN EN
ISO 8655-6 with a completely filled instrument and with uniform and smooth
dispensing up to the nominal or partial volume.
!
20 °C
Ex
The maximum error limit for a single measurement can be calculated EL = A + 2 CV.
The maximum EL for 25 ml size is ± 30 µl and for 50 ml size ± 50 µl.
This proves that the error limits for Class A burettes per DIN EN ISO 385
are met.
Note:
Comparison of error limits:
* A = Accuracy, CV = Coefficient of Variation ** EL = Error limits
Titrette
®
bottle-top burette
Requirements for piston
burettes according to
DIN EN ISO 8655-3
Glass burette
Class A acc. to
DIN EN ISO 385
Volume
ml
Partial volume
ml
A*
≤± % µl
CV*
≤ %
µl
A*
≤± % µl
CV*
≤ % µl
EL**
± µl
10
10
0.10 10
0.05 5
0.3
30
0.1
10
20
5
0.20 10
0.10 5
0.6
30
0.2
10
20
1
1.00 10
0.50 5
3
30
1
10
20
25
25
0.07 18
0.025 6
0.2
50
0.1
25
30
12.5
0.14 18
0.05 6
0.4
50
0.2
25
30
2.5
0.70 18
0.25 6
2
50
1
25
30
50
50
0.06 30
0.02 10
0.2
100 0.1
50
50
25
0.12 30
0.04 10
0.4
100 0.2
50
50
5
0.60 30
0.20 10
2
100 1
50
50
The titration volume is displayed in 1 µl graduations in the 10 ml and 25 ml instruments, and in 2 µl gra-
duations in the 50 ml instrument. Starting at a titration volume of 20 ml, there is an automatic conversion
to 10 µl graduations.
The drop size for the 10 ml instrument is approx. 20 µl, and for the 25 and 50 ml instruments approx.
30 µl.