Photometry; General Information - wtw pHotoFlex STD Manual

Operation
30
Menu item
Date format
4.5

Photometry

4.5.1 General information

Photometric measurements serve to determine chemical substances in liquid
samples. For this determination, the substance to be determined has to be
present in a form that is suitable for photometric measurement. At the same
time, possible disturbing factors have to be excluded.
Before measurement, the sample has to be pretreated in order to bring the
substance to be determined into the form that is suitable for measurement
and at the same time exclude disturbing factors.
Pretreatment of the sample is described in the analysis specification.
In a simple case, pretreatment can be to dissolve a solid substance in water;
it can, however, also include chemical conversions, e. g. a digestion.
The chemicals required in the analysis specification are available as test
sets.
Suitable analysis specifications for test sets can be found in the
photometry analysis manual (on CD-ROM).
There you will also find further instructions on handling chemicals
and on how to proceed when applying the analysis specifications.
Methods and the corresponding method data for many test sets are stored as
programs in the pHotoFlex
program.
The stored method data are loaded when the program number is entered or
read in with the aid of a bar code reader.
You can look up an overview of the available methods in the photometry anal-
ysis manual and display it on the screen of the pHotoFlex
section 4.5.8).
You can measure the following parameters with the pHotoFlex
 Concentration[mg/l]
 % Transmission []
 Absorbance []
Setting Explanation
dd.mm.yy Settings of time and date.
mm.dd.yy
mm/dd/yy
®
STD. A program number is assigned to each
®
pHotoFlex STD
®
STD (see
®
STD:
ba75958e07 11/2020