Raman System Considerations

By Bharat Mankani, Ph.D, Application Specialist at MarqMetrix, published in the August 2020 issue of Spectroscopy:

What Technical Requirements Should My Raman System Meet?

  • Laser wavelength: The most common wavelengths for Raman systems are 532nm, 785nm, and 1064nm. A 785nm wavelength system will achieve the right balance between Raman signal strength and reduced fluorescence
  • Software interface compatibility: Your Raman system’s software interface must be intuitive, and OPC-compatible with other process controls software. The software should interface with chemometrics process software and control multiple instruments if needed
  • Ease of setup and portability: Consider whether a scientist is required to set up and maintain your Raman system. Also, look at your instrument’s size and whether it is portable: the ability to install your Raman system at the point of need is essential. Reducing the cost of ownership by taking the scientist out of the science is imperative when using Raman for continuous process analysis and control

Factory calibration:  Choose a factory-calibrated instrument that can maintain its calibration for long periods. Calibration is an important factor for accurate and precise Raman analysis, and instruments that require regular calibration can impact your uptime and cause process disruptions.

Sample interface and sampling reproducibility: Look for a Raman manufacturer that offers a variety of sampling options: probes for immersion, stand-off probes for looking through vessels, and flow cells for simply connecting to your flowing process. The sampling probes should reduce sample variability and eliminate the reproducibility errors caused by improper focusing. For liquid and gas samples, consider adding a Raman flow cell inline to take sample measurements.

Sample optimization: Parameters to consider for signal optimization are laser intensity, exposure time, and signal averaging. If you are new to Raman, choose a manufacturer that will help develop and support your application with dedicated and experienced application experts to guide you through the development of your customized Raman solution.

Adaptability: Raman instrumentation is unique to each manufacturer, which can pose a challenge when a specific sample interface is required and is not provided by or is incompatible with your Raman system. Choosing an adaptable system increases usability and flexibility when using your system(s) for different applications.

The August 2020 issue of Spectroscopy is available here.

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