The Photometers; Photometric Test Kits; Basic Principle - wtw PhotoLab S12-A Operating Instructions Manual

1 Photometers

1.2 The Photometers

The photometers that belong to the Spectroquant
from con ven tional photo meters in the following important aspects:
•
The calibration functions of all test kits are electronically stored.
•
The measurement value can be immediately read off from the display
in the de sired form.
•
The method for the test kits (Cell Tests and reagent tests) belonging to
®
the Spectroquant analysis system is automatically selected via the
scanning of the bar code.
•
All cells formats used are automatically identified and the correct meas-
uring range is selected automatically.
•
Instrument-supported AQA ensures that measurement results can be
used as secure, reproducible, and recognized analytical results.
•
New methods can be downloaded from the internet site
http://photometry.merck.de and permanently stored in the instrument.
For technical data and instructions for use please refer to the section
"Function description" or can also be found on the internet.

2 Photometric Test Kits

2.1 Basic Principle

By means of reagents, the component of a sample to be analyzed is con-
verted into a coloured compound in a specific reaction. The reagents or
reagent mix tures contain – in addition to the reagent selective for a para-
meter to be determined – a number of auxi liary substances that are
essential for the course of the reaction. These include, for example, buffers
for adjusting the pH to the optimal value for the reaction, and masking
agents that suppress or mini mize the influence of interfering ions.
The colour reactions are in most cases based on standardized analytical
methods specifically optimized in terms of ease of use, a low working
effort, and shorter reaction times. Furthermore, methods cited in the litera-
ture or developed by ourselves are also used. Details on the respective
reference procedures are stated in the package insert or else in the para-
meter overview.
Release 01/2009
® Analysis System differ
photoLab ® Series
3