Analyzer Stability

An elemental combustion analyzer is able to measure the amount of Total Nitrogen, and Total Sulfur by means of high-temperature combustion (approximately 1000 ˚C) in an oxygen-rich environment.

By combusting sample material (Solid, Liquid or Gas ), NO and SO2 are formed which can be detected by a Pulsed UV-Fluorescence followed by a Chemiluminescence detector.

Our quartz combustion tube is constructed in such a way that it allows direct injection of the sample into the heated oxidation zone of the furnace and/or to accommodate the sample introduction using a quartz sample boat. The surface of the oxidation section of the combustion tube must be large enough to ensure complete oxidation of the sample. However, some elemental combustion analyzer manufacturers pack the quartz combustion tube with an oxidation catalyst to achieve this.

The XPLORER Series does not make use of oxidation catalyst: The unique construction of the Xplorer combustion tubes is designed in such a way, to always deliver sufficient oxidation power on samples that are difficult to combust.



Detection of Total Sulfur – UV-Fluorescence

When organic Sulfur components are combusted in the high-temperature furnace, the following reaction takes
place:

R-S+ O2→ SO2  + H2O + CO2

After complete sample oxidation, the combustion gas is conditioned by removing water vapor and particles.

The conditioned gas stream containing the Sulfur Dioxide (SO2) molecules is transferred to the reaction chamber.
The Xenon flashed UV lamp will excite the Sulfur Dioxide molecules to SO2(*) at specific wavelengths
and due to the unstable character of the SO2(*) it will relax back to SO2 instantly. The released
energy will be emitted in the form of light and will be detected by the Photomultiplier Tube (PMT). The amount
of light emitted equals the total amount of SO2 (Total Sulfur) present in the sample.

Detection:

SO2 + [g]1  à  SO2( *)

SO2( *) à SO2  + [g]1

Detection of Total Nitrogen – Chemiluminescence

When Nitrogen components are combusted in the high-temperature furnace, the following reaction takes place:

R-N+ O2→ NO + H2O + CO2

After complete sample oxidation, the combustion gas is conditioned by removing water vapor and particles.

Ozone is added to the conditioned gas stream in the Chemiluminescence reaction chamber. Ozone reacts with Nitric
Oxide (NO) to form Nitrogen Dioxide in an excited state (NO2*). The emitted light is detected by a Photomultiplier
Tube (PMT). The amount of detected emitted light corresponds with the amount of NO (Total Nitrogen) present in the
sample.

Detection:

NO+ O3  à NO2( *)  + O2

NO2(*)  à NO2  + [g]1

Days without calibration

Testing a led count 42