Process probes stand the test of time - after more than 25 Years of superior performance

Guided Wave Inc.,is still enjoying robust sales of theirSingle-Sided Transmission (SST) process insertion probes after more than 25 years in the marketplace. Over a quarter century ago, process probes for fibre optic spectroscopy were small, fragile devices with poor optical throughput, ill-defined path lengths and uncollimated light beams. In 1991, Guided Wave designed the SST Probe solving all these problems; thus making ‘in situ’ spectroscopy in the harsh, high temperature, high pressure world of the process environment practical. The SST Probe eliminated the need for complex sampling systems with their expense, maintenance, and lag times. By installing an SST probe in-line (in situ) in a pipe or reactor through a single access port, the process is directly monitored and measured without altering the substances being monitored. This pioneering probe was the first and original truly collimated, fixed path length, high transmission ruggedised fibre optic probe for in line process NIR spectroscopy.

In 1998, Guided Wave’s Dr. Terry Todd re-engineered the probe to improve the optical efficiency and further enhance its ruggedness and reliability. This pursuit of continuous improvement demonstrates a fundamental aspect of Guided Wave’s products and business practices.

this day, the SST remains one of the most copied, reliable, rugged, and efficient process insertion probes available. Prized for its robust, durable construction, and longevity in harsh process environments, the SST Probe continues to be valued by users and process engineers, worldwide, for the confidence it promotes in the quality of their data and, thus, their final product.

Dr. Terry Todd, states, “As virtual ‘windows into your process’, optical sample interfaces, or probes, must be designed to return reliable data even while installed in harsh environments. Recognising the probe as a critical component of the NIR and UV/VIS analyser system, Guided Wave has put as much into the design of our process probes and flow cells as we have put into our NIR and UV/VIS analysers.” Guided Wave Director of Sales and Service, James Low, adds, “Our customers have been able to rely on the SST family of probes over the past 25 years and this will continue far into the future. The SST’s design, engineering, and quality deliver high value over extended periods of time.”

Probe bodies are often built with 316L stainless steel, yet other materials (for example, Hastelloy C-276, Carpenter 20, Tantalum etc.) may be used as process conditions require. Sapphire optical windows are sealed to the body by proprietary gold alloy brazing technique for added longevity. By using the appropriate materials, an SST Probe will be unaffected by the potentially harsh chemical components and physical conditions of the process environment; thus providing many years of reliable data and superior performance. James Low, continued, “Initial long term quality of the SST probe has been excellent with no warranty issues”.

Ideal for continuous process monitoring applications any probe within the SST family is compatible with all Guided Wave fiber-optic analyser platforms – past, present, and future. Guided Wave probes also work with other brands of fiber optic analysers, according to fiber diameter and spectral range. Optional accessories make it easy to adapt the SST Probe to different kinds of process installations. The SST is available with UV-Vis or NIR optics and can be installed in pipes, reactors, vessels, kettles, etc. Operators can specify the wavelength range, fibre optic cable diameter, length, path length and materials of construction and opt for additional flanges to be mounted, additionally; an extractor mechanism is available for quick, safe, and convenient periodic maintenance. Optical path lengths are available from 2 to 50 mm and probe lengths from 12” to 30” [30 cm to 76 cm).

The SST offers high optical efficiency with its true collimated single pass optical sample interface. These probes are capable of operating in process temperatures of up to 300°C and pressures up to 2000 psi [13.8 MPa]. Additionally it features permanently sealed sapphire windows, with no o-rings to replace or leak, and water tight conduit ready fibre cable interface.

With thousands of Guided Wave process probes in use, in a wide variety of demanding process installations worldwide, Guided Wave fiber optic SST Probes have withstood the test of time.