Can Raman be used for remote in situ analysis?

Since Raman is a light scattering technique, it is possible to transfer both the laser excitation light and the Raman signal through optical fibre cables.  A single cable is used to transmit the laser to the sample, whilst another fibre is then used to transfer the Raman signal from the sample to a standard spectrometer and detection system.  These two cables are connected to a compact, rugged Raman probe head which focuses the laser onto the sample, and collects the Raman signal.

The current generation of Raman probes can be used for remote sampling hundreds of meters away from the base Raman analyzer.  In addition, multiple probes can be connected to a single analyser system, providing a cost effective method of monitoring chemical composition at multiple points within a plant.

The probes are suitable for use at high temperatures and pressures.  They can operate in either an immersion mode (where the analysis head is dipped within the reaction liquid) or in a stand-off mode (where the analysis is made by focusing the laser through a transparent window in the reaction vessel or pipeline).

Remote Raman analysis can be used for:

  • Solution/reaction mixes
  • Emulsions
  • Slurry and suspensions
  • Headspace in vials/reactors
  • Raw and bulk material feeds
  • Vessel cleaning effluents
4-20 mA output to a DCS remote control station and CSV file log output
4-20 mA output to a DCS remote control station and CSV file log output
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MORE INFORMATION

  • Visit our Application pages for further information about the practical use of remote in situ Raman analysis