Eppendorf Top Buret M / H - Manual (Page 28)

28
Calibration and adjustment
Top Buret
™
English (EN)
6.1.3 Evaluating the calibration
1. Compare the results for inaccuracy and imprecision with table (see p. 36).
2. If the errors are within the tolerance range specified in the table, no
adjustment is necessary.
3. If the errors are outside the tolerance range, adjust the device or contact a
service technician.
6.2 Adjusting the Top Buret
The Top Buret has been calibrated and adjusted before delivery. Adjust the Top
Buret in the following situations:
• The calibration error with distilled water is outside the tolerance range
• The density of the titrated liquid differs from the density of distilled water
Calibration is only possible with a testing volume between 10 mL – 90 mL.
3. Calculate the inaccuracy (e
s
) using the nominal volume
(V
s
).
• = actual volume (average value of the weighings)
• V
s
= nominal volume (Top Buret M = 25 mL, Top Buret H
= 50 mL)
4. Calculate the standard deviation (s
r
).
• s
r
= standard deviation
• n = number of dispensing steps
• V
i
= measured value (weight of the sample)
• = actual volume (average value of the weighings)
5. Calculate the imprecision (CV).
V
e
s
= × 100 %
V – V
s
V
s
V
(V
i
– V)
∑
n
i = 1
n – 1
s
r
=
V
100 × s
r CV =