ELTRA CS 800 analyzer
Analyses of carbon and sulfur concentrations in metals, plants, and rocks are performed at the institute by using an ELTRA CS800 instrument. The sample material is weighed into a ceramic crucible. Iron and tungsten chips are then added to support later melting and oxidation of the sample. The crucible is transferred into a sealed furnace which consists of an induction coil with the crucible resting in the centre of the coil. Induction of a strong magnetic field melts the iron and tungsten additives and ultimately also the sample material, and addition of oxygen oxidizes the released carbon and sulfur as CO2 and SO3, respectively. These gases are transferred to and detected by an infrared detection unit. The measured intensities are then converted into concentrations of C and S or CO2 and SO3, respectively (user's choice).
Sample material must be dry and relatively fine grained, rock samples should be ground to < 2 µm. Metals, rocks, minerals, soils, and dry organic material can be analyzed.
Typically less than 200 mg, depending on the expected C and S content; rock samples 100 to 200 mg
Two separate infrared detection channels for C and S, which can be switched of separately (e.g., if a sample contains high C contents that would saturate the detector, but low S contents)
Limit of detection:
ca. 6 µg for C and 5 µg for S
Typically less than 60 seconds, including background determination and signal stabilization
Several certified metal and two silicic standards (granite, cement), plus some self-made in-house standards