744 Series Combustion

Carbon and Sulfur by Combustion

With our 744 series, you may redefine how you determine carbon and sulphur in metals, ores, and other inorganic materials. The 744 takes advantage of our immersive Cornerstone® brand software platform and a number of features, such as an improved IR cell design and available automation, come together to increase usability, lab productivity, and lower your cost-per-analysis, thanks to extensive customer feedback and innovative engineering.


Furnace with a high frequency.

  • To encourage complete combustion, an integrated oxygen lance supplies the crucible with high-purity oxygen.
  • Induction furnace with a frequency of 18 MHz and a power of 2.2 kW for fast and steady burning.
  • Autoloaders with 10- and 60-sample capacity are available as options for hours of worry-free operation.
  • Dust and debris are kept contained using a high-velocity vacuum system.
  • Design of the IR cell has been improved.
    Increased protection from ambient temperature variations is provided by temperature stabilised structure.
  • IR cell lifetime and long-term stability are improved by improved emitter control and detection circuitry.

Theory of Operation

The CS744 carbon/sulfur analyzer is designed to evaluate carbon and sulphur content in metals, ores, ceramics, and other inorganic materials over a wide range of temperatures. The instrument is equipped with bespoke software that is optimised for touch operation.

RF induction is used to heat a pre-weighed sample of around 1 gramme that is combusted in a stream of oxygen. Carbon and sulphur in the sample are oxidised to CO2 and SO2, then swept by the oxygen carrier through a drying reagent and into an NDIR cell, where sulphur is detected as SO2. The gas flow continues past a heated catalyst, where carbon monoxide (CO) is transformed to CO2 and sulphur trioxide (SO2) is turned to SO3, which is then filtered out. Another NDIR cell then detects carbon as CO2. To avoid interference from natural variations in atmospheric pressure, a pressure controller is utilised to maintain constant pressure in the NDIR cells. The final component in the flow stream is an electronic flow sensor, which is used to monitor the carrier flow for diagnostic purposes.

CO2 and SO2 absorb infrared (IR) light at distinct wavelengths within the IR spectrum, which is how non-dispersive infrared cells work. As gases move through IR absorption cells, incident IR energy at these wavelengths is absorbed. Unknown sample concentrations are determined in relation to calibration standards. Prior to each study, reference measurements of pure carrier gas are taken to reduce interferences from instrument drift.