wtw Turb 550, Руководство по эксплуатации

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Operation
27
4.3 Calibration
Why calibrate? As with every measuring instrument, the measuring accura-
cy of the turbidity measuring instrument must be checked
and adjusted at regular intervals.
For this purpose, 3 calibration standards (1000 NTU, 10
NTU, 0.02 NTU) that were specially developed for this in-
strument are supplied with the instrument.
Note
Always use the calibration standards that were delivered
with the instrument to calibrate it. Check that they have not
passed the expiry date!
Note
Basically, for measurements according to DIN/ISO and also
for standard methods, calibrations with formazin are re-
quired. See Application report 998 255 H
ERSTELLUNG VON
F
ORMAZIN
-P
RIMÄRSTANDARD
(P
REPARATION OF
F
ORMAZIN
P
RIMARY
S
TANDARD
) for more information.
Preparatory
activities
Perform the following preparatory activities if you want to
calibrate:
Warning
Never open the cells containing the calibration standard!
1 Switch on the measuring instrument
2 Wait for the 30 minute warm-up time
3 Have the calibration standard ready
4 Make sure that the outside of the cell is clean, dry and
free of fingerprints.