Measuring method
multi EA 4000 Version 01.16 45
Without using the automatic TIC solids module hydrochloric acid is added to the solid sample
on the combustion boat to remove the inorganic bound oxygen. The CO
2
resulting from the
reaction from the carbonates evaporates. The wet sample with added hydrochloric acid is
dried in the drying cabinet at < 40 °C for at least 3 hours and the excess hydrochloric acid
evaporates. The sample prepared in this way can then be examined in the analyzer for inor-
ganic bound carbon as in the TC/TS analysis.
IMPORTANT
Because the acid only releases CO
2
from carbonates and hydrogen carbonates, elementary
carbon or carbon from carbides, cyanides, cyanates, isocyanates and thiocyan
ates is also
5.4 Carbon detection after pyrolysis: TC-EC
(optional)
The detection of the carbon content of a sample is carried out in four steps in the optional
pyrolysis mode.
The original sample is weight in two boats – boat 1 and boat 2.
1. The sample in boat 1 is first pyrolyzed in the argon flow. At the preset temperature vola-
tile components of the enclosed carbon compounds escape. In the ideal case and / or
after appropriate pretreatment the elementary carbon (EC) remains on the boat.
2. The share of the remaining carbon (EC) in the already pyrolyzed sample is detected by
combustion in the oxygen flow.
3. The sample in boat 2 is converted in the oxygen flow to detect the total carbon content
(TC).
4. From the difference of the two measured values (TC and EC) the volume of degradable
or active carbon can be deducted.
5.5 Data analysis in the C/S mode
5.5.1 Calibration techniques
Every parameter (procedure) of a method can be calibrated. The parameters of a method to
be calibrated can be individually defined. Not all parameters need necessarily be calibrated.
For every parameter up to three calibration functions can be stored in a method. The alloca-
tion is automatic.
The calibration function is calculated related to mass. Linear and quadratic calibration func-
tions are calculated in accordance with the equations (5) and (6) through regression calcula-
tion.
=
(
×
+
)
/ (5)
= (
×
+
×
+
)/ (6)
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