multi EA 4000
Measuring methods
45
The correlation coefficient compares the dispersion of the calibration measuring points
of the regression function with the total dispersion of the calibration. If all calibration
measuring points are on the calculated regression function, the correlation coefficient
is +1 or -1. With a positive correlation coefficient the regression function is increasing,
with a negative coefficient it is decreasing.
The square of the correlation coefficient is called the coefficient of determination.
4.5.4
Other calculations
For all measurements where multiple determinations are carried out the average value
(AV), standard deviation (SD) and variation coefficient (VC) are calculated and dis-
played. For each sample a triple determination can be carried out as a maximum.
For measurements of TOC with the automatic TIC solids module in the differential
method or determination of carbon after pyrolysis (TC-EC) only a single determination
takes place.
The average value of the final result is calculated from the concentrations determined
for the individual detections.
The boat blank is determined by introducing an empty boat or a boat with additives for
the sample into the combustion furnace and analyzing it.
The boat blank value can be determined separately and entered in the control and
analysis software multiWin. This value can change over time and must be
redetermined before the start of each measuring series. Otherwise the value last
entered will be used.
4.6
Cl determination
The samples to be examined are fed to the combustion chamber in a quartz glass boat
via an open gas sluice. The sample is first pyrolized in the inert gas flow (argon). The
resulting pyrolysis products are completely incinerated in the oxygen flow with some
delay.
The reaction is based on the following equation:
R-Cl
HCl + CO
2
+ H
2
O + Oxide
(8)
The HCl share is determined by way of coulometry after measuring gas drying. In this
the chloride ions react fully with electrolytically generated silver ions to form silver
chloride.
Ag
Ag
+
+
e
-
(9)
Ag
+
+ Cl
-
AgCl
(10)
From the charge used up to generate the silver ions it is possible to calculate the chlo-
ride volume based on Faraday's law.
Correlation coefficient
Coefficient of
determination
Average value
Boat blank
Summary of Contents for Analytik Jena multi EA 4000
Page 1: ...Operating Manual multi EA 4000 Elementary analyzer C S and Cl solids analysis...
Page 50: ...Commissioning multi EA 4000 50 Figure 32 multi EA 4000 C S Hose diagram...
Page 52: ...Commissioning multi EA 4000 52 Figure 33 multi EA 4000 Cl Hose diagram...
Page 54: ...Commissioning multi EA 4000 54 Figure 34 multi EA C S Cl for C S measurements Hose diagrams...
Page 55: ...multi EA 4000 Commissioning 55 Figure 35 multi EA 4000 C S Cl for Cl measurements...
Page 57: ...multi EA 4000 Commissioning 57 Figure 36 Automatic TIC solids module Hose diagrams...
Page 58: ...Commissioning multi EA 4000 58 Figure 37 multi EA 4000 C S with automatic TIC solids module...
Page 61: ...multi EA 4000 Commissioning 61 Figure 39 multi EA 4000 C S Cl with man TIC solids module...
