Coding Decomposition Vessel; Oxygen Station C 248; Calorimetric Measurements; Determining The Calorific Value - IKA C 200 Operating Instructions Manual

4.8 Switching off the system
Standby mode
In order to switch off the calorimeter system, the
start screen must be displayed.
Press OFF (F1). The appliance will switch to
standby mode.
Switching off
Only switch the appliance off in standby mode.
To do this, press the ON/OFF switch  (see sec-
tion 4.2) on the back of the appliance.
4.9 Coding decomposition vessels
TIP You can use several decomposition vessels (max.
4) when working with calorimeter C 200. You
can code these to distinguish between them by
sticking the black coding strips into the special
slots on the decomposition vessels.
Decomposition vessel no.:
1
without coding
Slot for
coding strips
3

4.10 Oxygen station C 248

The C 200 does not have an integrated oxygen
filling point for the decomposition vessel. You
can use oxygen station C 248 for filling. The C
248 oxygen station must be set up at least 1.5 m
far away from the calorimeter. For information on
how to operate and connect the oxygen station,
please see the accompanying operating instruc-
tions.
Operation:
• Place decomposition vessel C 5010 on the
marked position.
• Move the lever  down and centre the de-
composition vessel below the fill head .
• Lock the lever in place.
• Fill the decomposition vessel for approx. 30
secs.
• Move the lever back to its original position.

Lever
2

Fill head
4
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Calorimetric measurements

In many cases, however, not just the combus-

5.1 Determining the calorific value

tion products referred to in the standards are
produced. In such cases the fuel sample and the
Combustion is carried out in a calorimeter under
specific conditions. The decomposition vessel is combustion products must be analysed to pro-
vide data for a revised calculation. The standard
filled with a weighed fuel sample, the fuel sample
calorific value is then calculated from the measu-
is ignited and the temperature increase in the ca-
red calorific value and the analysis data. The heat
lorimeter system measured. The specific calorific
value of the sample is calculated as follows: value Hu is the same as the calorific value, minus
the condensation energy of the water contained
in the fuel and formed through combustion. The
Ho = (C * DT - QExt1 - QExt2) / m (1)
heat value is the more important parameter from
a technical point of view because in all major,
m
Weight of fuel sample technical applications only the heat value can be
evaluated in terms of energy.
C
Heat capacity (C-value) of calorimeter system
The complete bases of calculation for the calori-
fic and heat value can be found in the relevant
DT
standards (e.g.: DIN 51 900; ASTM D 240; ASTM
Calculated temperature increase of water in inner
D 5865..). They are also contained in the CalWin
vessel of measuring cell
calorimeter software.
QExt1
Correction value for the heat energy generated

5.2 Corrections

by the cotton thread as ignition aid
Due to the nature of the system a combustion
QExt2
test does not just produce the combustion heat
Correction value for the heat energy from other
of the sample, but also heat from external energy
burning aids
(QExternal).
This can fluctuate considerably in relation to the
The decomposition vessel is filled with pure oxy-
heat quantity of the fuel sample.
gen (99.95 %) to optimise the combustion pro-
cess. The pressure of the oxygen atmosphere in
the decomposition vessel is max. 30 bar. Formula
(1) for the calorific value of a material requires
that combustion takes place under specifically
defined conditions. The relevant standards are
based on the following assumptions:
• The temperature of the fuel and its combustion
products is 25 °C.
• The water contained in the fuel before combus-
tion and the water formed whilst combusting
the hydrogenous compounds of the fuel is in
fluid form after combustion.
The combustion heat of the cotton thread which
• The atmospheric nitrogen has not oxidised.
ignites the sample and the electric ignition energy
• The gaseous products after combustion consist
would distort the measurement. This influence is
of oxygen, nitrogen, carbon dioxide and sulp-
taken into account in the calculation by way of a
hur dioxide.
correction value.
• Solid materials may form (e.g. ashes).
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