Inline Transmission Probe For FT-NIR Measurements

The Single Sided Transmission (SST) Probe designed and manufactured by Guided Wave is ideal for continuous NIR process monitoring applications. The corrosion resistant design enables FT-NIR measurements in any 1 inch or 3/4 inch diameter access port. The SST Probe is compatible with any Guided Wave analyzer and many other analyzer brands. Optional accessories such as the Gear Drive Probe Extractor or welded flange make it easy to adapt the SST Probe to different kinds of process installations. This unique, compact design (U.S. Patent #6,043,895) means true transmission which translates to more signal, less noise, better measurements.

Drawing Single-Sided Transmission (SST) Process Probe
General design of the NIR insertion process probe.

Anatomy of an Insertion FT-NIR Process Probe

Process Compatible Seals Prevents Leaks

high quality Gold Alloy fillet used to seal an FTNIR Insertion Probe.
Image shows the high quality gold alloy fillet used to seal the FT-NIR Optics.

Every insertion probe built by Guided Wave must pass our standard negative pressure helium leak test. This test ensures that the insertion probe is properly sealed for most FT-NIR applications. Improve operator safety and reduce downtime by selecting one of three process compatible seals.

  1. The GEORO Braze – Our standard seal uses a gold based alloy to provide a hermetical seal around the optics and prevent the process from penetrating into the internal optics of the insertion probe.
  2. The NIORO Braze – Developed specifically for high temperature low viscosity processes this nickel based alloy provides a hermitical seal with a small grain boundary. The small grain size reduces the ability of inclusions from allowing the process to leak into the internal optics.
  3. The O-ring Seal – Either Viton or Kalrez o-rings can be selected to seal the optics from corrosive environments where the metal braze would be attacked.

Additionally, the probe body can be built out of 316 stainless steel, 304 L, Hastelloy, or other corrosive resistant metal.

Exceptional Light Transmission for FT-NIR Measurements

Like other Guided Wave optical probes, the SST Probe provides exceptional optical performance. Typically, peak transmission exceeds 40%. That means more signal, lower measurement noise, and lower limits of detection. Of course, the SST Probe’s optics are permanently aligned at the factory. There’s no need for optical adjustments at the time of installation, nor ever any chance for misalignment or varying pathlengths.

The Insertion Probe is Compatible with Bruker Matrix-F and ABB FT-NIR Spectrometers

The insertion probe is manufactured by Guided Wave to facilitate full integration with any fiber-optic spectrophotometer manufacturer. The insertion probe is fully compatible with the Matrix-F FT-NIR analyzerABB’s full line of FT-NIR spectrometers, and AIT’s optical analyzers. The market leading optical efficiency of our sample interfaces will improve the optical performance any spectrometer when connected with 400 to 600 micron fiber optical cables and SMA 905 or FC connectors. The NIR-O Full Spectrum DG-NIR Spectrometer and Clearview DB photometer are the only analyzers engineered to be ‘’optically matched’’ with Guided Wave probes.

Custom FT-NIR Probe Designs Available

Guided Wave offers a variety of probes, flow cells and fiber optic cables that meet the harsh demands of the process environment. Several have auxiliary features and are compatible with all Guided Wave analyzers. They are also compatible with many fiber optic FT-NIR based analyzers manufactured by other companies.

Most of our probes and flow cells can be optimized for the UV, visible, or NIR spectral regions or supplied with custom fiber diameters and connectors to match your optical requirements. However, if we do not have a probe or flow cell that meets your precise need, Guided Wave has the experience and expertise to design a custom solution for your particular process installation. Please contact us with your requirements. A flange seal can be added to the SST probe upon request.   All purchases of Flanged SST Probes require a customer signoff drawing to confirm the location and dimensions of the flange.

Product NameSingle Sided Transmission Probe (SST)
Sample Interface TypeNIR, UV-Vis Probe
Product Part Number
Body Material 316L SS standard; 304 SS, 316 SS, Hastelloy C-276, Monel, Titanium and Nickel, other available on request
CompatibilityCompatible with all Guided Wave analyzers and many other commercial brands
Efficiency > 30% for pathlengths < 20 mm
Fiber Diameter (μm)/Connector 400; 500; 600 / SMA 905; FC; ST others available on request
Fiber Types Deep UV (UV-Vis); or Ultra Low-OH (Vis-NIR)
Mounting Swaged Fittings, custom flanges; extractor assembly mechanism option (document #1046)
Optics Fused silica (UV-Vis); BK7 (Vis-NIR)
Pathlength (mm ± 0.075 mm) 2; 5; 10; 15, 20; 50 (exact pathlength engraved on all probes)
Pressure Range 0 psi to 2000 psi [0 – 138 bar] higher pressures available on request
Probe Diameter (inches) 0.750 [19 mm]; 1.000 [25.4 mm] (larger diameter recommended for probes !24” long)
Spectral Range UV-Vis (230 – 600 nm); Vis-NIR (380 – 1100 nm); NIR (800 – 2100 nm)
Standard Probe Lengths 12; 18; 24; 30, 36 (;inches) longer lengths available on request