wtw Turb 350 IR, Руководство по эксплуатации, Страница: 23 / 42

Operation
65
4.3.3 Preparing the calibration
Perform the following preparatory activities when you want
to calibrate:
Warning
Never open the cuvettes containing the calibration stan-
dards.
4.3.4 Four-point calibration
Calibration
sequence
The four-point calibration according to the calibration pro-
gram calibrates the instrument using the following calibra-
tion standards in the following order:
1000 > 100 > 10.0 > 0.02 NTU
Note
If, after the end of a calibration step, you do not resume the
calibration within 5 minutes, the instrument automatically re-
turns to the normal measuring mode. It will then continue to
work with the previous calibration data.
Calibration To calibrate your measuring instrument using the calibration
program, proceed as follows:
1 Have the required calibration standards ready.
2 Make sure that the outsides of the cuvettes are clean,
dry, and free of fingerprints.
1 Switch on the turbidity measuring instrument by
pressing the key. Let the turbidity measuring in-
strument warm up for at least 75 s.
2 Press the key. CAL 1 appears on the display. This
indicates that you should insert the no. 1 calibration
standard (1000 NTU).