How to Select an Analyzer

Selecting a light, or spectroscopy, based in-line process analyzer can be an intimidating task. You may find yourself asking questions like; What is the difference between a photometer and a spectrometer? What wavelengths do I need to monitor for my application? Do I need to buy a UV/VIS, NIR, or MIR analyzer? To aid you in the decision making process Guided Wave has developed a three-step process to answer these questions.

Once these questions are answered, you can confidently move onto comparing technologies such as the difference between DG-NIR and FT-NIR or manufacturer specifications like repeatability.

infographic outlining how to select a spectroscopic analyzer

Step 1 – What is being measured?

The first step in selecting the proper analyzer for an application is achieved by identifying what properties and chemical species of the process you want to monitor. Using the image below locate as many wavelengths as possible that match the chemical structures of interest.

Chemical structure absorbance wavelengths
Gold = UV absorbers such as Chlorine; Red = Color and Metal Complex;
Blue = Water, Alcohol, and Phenol bonds; Purple = Organic carbon-hydrogen bonds; and Black = Nitrogen Bonds.

508plus Measurement/ Application Solutions – Examples

NIR-O Measurement/ Application Solutions – Examples

Clearview DB Measurement/ Application Solutions – Examples

Photometers such as the Clearview DB use a fixed number of solid state optical filters to monitor up to 6 discrete wavelengths. Photometers provide a cost-saving option for less complex processes.

The discrete wavelengths for four common Clearview applications; (blue) Acid Number, (red) ASTM or Saybolt Color, (yellow) Polyol, (grey) Caustics in water, can be found in the image below.

example clearview applications

Step 2A – Identify the Corresponding Analyzer

using the informatin in step 1 idenify the corresponding analyzer

Now that the wavelengths of interest have been identified, simply match those wavelengths to an analyzer that can measure them. The image above indicates the wavelength range covered by the UV/VIS 508 Spectrometer, the NIR-O Full Spectrum Near-Infrared Analyzer, and the Dual Beam Clearview Photometer. If less than 6 wavelengths were identified, then a Clearview DB can possibly provide a cost-saving solution for real-time monitoring of process conditions.

Step 2B – Quick View and Comparison Selection Guide:

Still unsure which analyzer is best or your application? Now you can compare some high-level specifications such as the number of simultaneous sample points, wavelength range, technology type, the number of traits or answer the analyzer can monitor at each sample location.

Get a copy of the Analyzer Infographic

ANALYZER PURPOSE OR APPLICATION508plusCLEARVIEW® DBNIR-O
Wavelength Range required for measurementsUV-VIS 200-850-nmVIS - NIR 450-2150 nmNIR 1000-2100 nm
Diode Array - Spectrometer
Full Spectrum - DG-NIR Spectrometer
Dedicated Spectrum - Filter Photometer
Complex Samples with Variable Chemistries
Complex Samples with Many Measurements
Simple Well-Characterized Process
Number of Measurements (answers / results)16 per Channel6Unlimited
Maximum Number of Sample Points (locations)4212

Step 3 – Contact a Guided Wave Sales Representative

The final step can be completed in several ways

  1. Complete the Application Questionnaire to provide a Guided Wave Sales Representative everything they might need to know to help design a complete process monitoring solution.
  2. Fill out the Guided Wave Contact Us or RFQ Form. To receive additional information.