wtw Turb 555, Руководство по эксплуатации

Страница: 21 / 82

Turb 555 / Turb 555 IR Operation
21 ba41113e07 04/2009
Measuring methods The Turb 555 /Turb 555 IR can measure with different mea-
suring methods. To do so, the measuring signals of the four
detectors are evaluated differently.
The specified measuring unit determines whether a 90°
scattered light measurement or a transmission measure-
ment is performed.
Note
A Ratio measurement is only possible if you have selected
NTU or FNU as the measuring unit.
Nephelometric
(90° scattered
light) measure-
ment The rays of the undissolved particles
scattered in a 90° angle are mea-
sured. The measuring result is given
in NTU or FNU.
Transmission
measurement The intensity of the rays going
through the sample is measured.
The measuring result is given in
FAU.
Ratio
measurement The relation of the transmission
measurement to the 90° scattered
light measurement is measured.
This procedure compensates for the
light that is reduced by the color of a
sample. The measuring result is giv-
en in NTU (Ratio) or FNU (Ratio).