This website is dedicated to exploring and recommending flow cells and direct insertion probes for process spectroscopy applications. These probes or sample interfaces are ideal for measuring liquids, vapors, and gases with Dispersive or FT-NIR Process Spectrometers. Additionally, sample interfaces discussed here within can be modified specifically for UV-VIS process analysis. 

Discover Our Recommended Sample Interfaces
Direct Insertion Probe for PAT Spectroscopy

Direct Insertion Probes

Designed specifically for reactors and pipelines greater than 3 inches, Direct Insertion Probes allow for fast and non-destructive transmission measurement of the process. Optionally, a flange can be welded to the probe.

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Metal free Flow Cell for PAT FT-NIR Applications

Liquid Flow Cells

Designed specifically for at-line measurements Flow Cells are constructed in Teflon, 3016L Stainless Steel, and other custom alloys. Ideal for applications with small diameter pipes or sample conditioning systems. 

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Shuttle Probe Designed for inline PAT measurement sin the Polymers Industry

Inline Shuttle Probe

Developed for high-temperature polymer applications, the inline Shuttle Probe, is bolted into a pipe. The process fluid then flows through a retractable optical path piece. By retracting the rod, the path piece can be routinely serviced without shutting down the process.   

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Negative pressure Vapor Probe for Sterilization and other vacuum applications.

Negative Pressure Vapor and Gas Probes

Designed specifically for use in vacuum chambers with Triclover flanges, the gas and vapor probe is ideal for sterilization applications. 

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PAT Flow Cell for Trace Gas FT-NIR Detection

Positive Pressure Vapor and Gas Probes

Developed for trace gas detection, the Transmission Gas Flow Cell is ideal for long path length positive pressure applications. The Gas Flow Cells are constructed in 316L Stainless Steel and other custom alloys.

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Mechanical Extractor for PAT Probe

Accessories – Custom Flanges and Mechanical Extractors

The practical methods for removal of the probe from the process, access to the windows, or complete disassembly and reassembly abilities are often desirable features to look for when choosing new sample interfaces. For direct insertion probes, the type of seal to the pipeline or reactor determines the effort required to service.

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Discover Our Recommended Sample Interfaces

Frequently Asked PAT and Sample Interface Questions

What are the Fundamentals of a Fiber Optic Probe?

A basic diagram of a process transmission probe. All the key elements are present. Specific probes may vary significantly in layout and implementation.

What should I Consider for Solving Real World Measurement Problems?

When buying a flow cell or probe for an FT-NIR, NIR or UV-VIS analyzer system here are some questions to consider.

Selecting the Best Sealing Technology for Direct Insertion PAT Probes

Insertion probes are commonly sealed with O-rings. However other seal technologies such as gold alloy brazes are available for improved survivability over the life of the probe. 

Things to Consider before purchasing Probes and Flowcells PAT

The flowchart discusses what questions should be asked when selecting a sample interface for process Spectroscopy.

What are some examples of sample interfaces for specific applications?

We have compiled a list of applications and recommended sample interfaces.

Sample Interface (Probes and Flow Cells) Used in Spectroscopy

Online process measurement with FT-NIR, NIR or UV-VIS spectroscopy will involve a sample interface. The sample interface is a critical element of any process analyzer system.

The Virtual View into the Process

The sample interface consists of a probe or flow cell which is designed for use with fiber optic cables that are coupled to the analyzer. While probes and flow cells are predominantly passive devices in an otherwise active measurement system, their physical and optical properties can significantly add to or detract from the desired measurement. Effective pathlength, optical properties such as throughput, collimation, aberrations, sensitivity to vibration, sensitivity to thermal changes, and the quality of fiber connectors are important parameters in a probe design.

The Point Where the Light Meets the Sample

FT-NIR, NIR and UV-VIS spectroscopists use a wide variety of sample interfaces because the samples measured come in a variety of states and conditions. Samples may be powders, pellets, grains, low viscosity liquids, high viscosity liquids, slurries, or gases. Physical conditions may vary from ambient temperature and pressure to several hundred degrees Celsius and hundreds of atmospheres. Solid samples can vary from fine powders, such as flour, to corn flakes, dog food pellets or soda bottles. Additionally, safety is always a concern as samples may be flammable, explosive, corrosive, toxic, or environmentally regulated.

Consequently, the probe or flow cell must be capable of accurate spectroscopic measurements and be rugged enough to withstand the rigors of continuous duty in a harsh chemical and physical process environment, while providing optimal transmission for long-term reliable measurements. Above all, they must be safe.

For More Information on Sample Interfaces Contact Guided Wave