GUIDED WAVE’S Single-Sided Transmission (SST) Probe is our most popular fiber optic probe. On the market for over 25 years, it has been the most widely copied probe design in the industry. Rugged and reliable, it’s ideal for continuous process monitoring applications. Easily installed in a pipe or reactor through a single access port, the SST Probe is compatible with any Guided Wave analyzer and many other analyzer brands. Optional accessories make it easy to adapt the SST Probe to different kinds of process installations.

SST Probe Features

  • Corrosion resistant construction
  • Rugged and vibration resistant design
  • Sealed against ambient moisture infiltration
  • High optical throughput for low noise spectroscopy
  • Temperatures to 300 °C
  • Pressures to 2000 psi or 138 bar
  • Higher pressures are available on request

This probe is available in five standard lengths and six optical pathlengths. Other probe lengths and pathlengths are available by special order.

Guided Wave supports various types of flanges on the SST Probe. A partial list is provided for reference: DN25 PN40, DN125 PN16, 1” Class 150 RF, 4” Class 1500, and other

Exceptional Light Transmission

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.

Unique Insertion Probe Design

The SST probe houses incoming and outgoing optical-fibers side-by-side in a single 3/4-inch, or 1 inch stainless steel body. This unique, compact design (U.S. Patent #6,043,895) means true transmission which translates to more signal, less noise, better measurements.

Process-Resistant Probe Body Construction

The SST Probe is designed to withstand harsh process conditions. The body of the probe is built from 316L stainless steel or, by special order, other corrosion resistant materials. The SST Probe’s sapphire optical windows are sealed to the probe body with proprietary gold alloy brazing. These materials are unaffected by most hydrocarbons and polymers. For extremely corrosive process streams, use the O-Ring SST Probe instead (for details, see O-Ring SST Probe data sheet). Additionally, our special construction techniques also make the probe insensitive to most process pipe vibrations.

Compatible with All Guided Wave Analyzers and Many Other Analyzer Brands

The probe, or sample interface, is a crucial component of a complete analyzer system. For optimal performance, the probe must be ‘’optically matched’’ with the spectrometer and with the optical fiber that transmits the spectral signal. The SST Probe (and each of Guided Wave’s other optical probes) is matched to Guided Wave analyzers and fiber to achieve the highest possible performance. Guided Wave probes also work with many other brands of fiber optic analyzers, according to fiber diameter and spectral range.

Optional Accessories

The SST probe is available with optional accessories for easy adaptation to different kinds of process installations. The Extractor Assembly Mechanism allows for quick and easy removal and servicing of probes without shutting down the process. Our custom flange service facilitates installation of the SST Probe into common process pipe configurations.

Large Variety and Custom 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.

Figure 1: Anatomy of an SST Process Probe Saybolt Color Analyzer Enclosure

Specifications Single-Sided Transmission (SST) Process Probe

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