O-Ring Single Sided Transmission Probe For Process Sampling

GUIDED WAVE recommends the use of the O-Ring Single Sided Transmission Probe or O-SST, when an in-process fiber optic probe is needed in a corrosive process stream containing strong acids, bases, or cyanides. The O-SST performs similarly to our more popular gold alloy sealed SST probe, but uses polymer o-rings to seal the sapphire windows. Like the SST probe, the O-SST has high optical throughput for low noise inline spectroscopy of complex solutions. Inline probes eliminate costly and problematic fast loops and sample systems. The O-SST is available in several convenient pathlengths, probe lengths, o-ring  materials and most common chemically resistant stainless steel alloys.

O-SST Probe Features

  • Corrosion resistant construction
  • Rugged design
  • O-ring process seals
  • Sealed against ambient moisture infiltration
  • High optical throughput for low noise spectroscopy
  • Collimated beam for accurate

Process-Resistant Construction

The O-SST Probe is designed to withstand corrosive processes especially those containing nitric acid or cyanides that attack our gold alloy sealed SST probe. The body of the probe is built from 316L stainless steel (standard, however, several other alloys are available by special order). The probe’s sapphire optical windows are sealed to the probe body with polymer o-rings chosen to be compatible with your process. For assistance with choosing the best o-ring material, please consult the DuPont™ Elastomers website. The probe can be dismantled for periodic o-ring service, although we recommend that this be done at Guided Wave to ensure optimum performance. On request, the O-SST can be supplied welded to an ANSI or DIN process flange. Like our other probes, the O-SST is sealed against ambient moisture infiltration. All purchases of Flanged O-SST Probes requires a customer signoff drawing to confirm the location and dimensions of the flange.

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Operating Range and Configurations

The operating range of the O-SST Probe will be determined primarily by the choice of o-ring material. The maximum operating temperature and pressure are 250°C and 1000 psi. This probe is available in five standard lengths, nine optical pathlengths, and UV, visible and NIR versions. Other probe lengths and pathlengths are available by special order.

Exceptional Light Transmission

Like other Guided Wave optical probes, the O-SST Probe provides exceptional optical performance. Typically, peak transmission exceeds 40%. That means more signal, lower measurement noise, and lower limits of detection.

Compatible with All Guided Wave Analyzers

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 data. The O-SST Probe (and each of Guided Wave’s optical probes) is matched to Guided Wave’s analyzers and fiber to achieve the highest possible performance. It is also compatible with many other fiber optic analyzer brands according to fiber diameter and spectral range.

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 based analyzers manufactured by other companies.

Most of our probes and fl ow 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.

Figure 1: Anatomy of an O-SST Process Probe

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Specifications: O-Ring Single Sided Transmission (O-SST) Process Probe

1Product NameSingle Sided Transmission Probe (OSST)
2Sample Interface TypeNIR, UV-Vis Probe
3Product Part Number
Body Material 316L SS standard; 304 SS, 316 SS, Hastelloy C-276, Monel, Titanium and Nickel, other avaialbe on request
CompatibilityCompatible with all Guided Wave analyzers and many other commercial brands
Optical Efficiency > 30% for pathlengths < 20 mm
Fiber Diameter (μm)/Connector 400; 500; 600 / SMA 905; FC; ST others available on request
Fiber TypesDeep UV (UV-Vis); Low-OH or Ultra Low-OH (Vis-NIR)
Mounting Swaged Fittings, custom fl anges; extractor assembly mechanism option (document #1046)
Optics Fused silica (UV-Vis); BK7 (Vis-NIR)
Pathlength (mm ± 0.075 mm) 1; 2; 5; 10; 15; 20; 30; 40; 50 (other lengths available on request)
Pressure Range 0 psi to 1000 psi [0 – 69 bar]
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
Temperature RangeDetermined by o-ring material but not to exceed -25 °C to 250 °C
Window Material Sapphire (Vis- NIR) or Fused Silica (UV)
Window Seal Polymer o-ring material of your choice including Kal-Rez and Viton (contact Guided Wave for alternatives)