Resistant and safe transmission probes

For spectroscopic applications under the harshest process conditions

Excalibur HD FPT Transmission Probes

Fiber-optical process probe for transmission measurements under harsh process conditions

The transmission probes of the »Excalibur HD FPT«  series for spectroscopic process analysis technology (PAT) were specially developed to achieve maximum safety and cost control under the toughest application conditions. State-of-the-art manufacturing technologies guarantee the highest precision for the best measurement results.

Excalibur HD FPT Series transmission probes provide highest robustness combined with high photometric transmission and accuracy for a wide range of process applications, especially for extremely demanding applications in rough process environments like high temperatures, thermal shocks or when using aggressive chemicals.

A distinctive feature of the »Excalibur HD FPT« probes is the use of light guides instead of internal optical fibers. This has a significant benefit in terms of temperature stability and allows their use at both, very high and very low process temperatures.

The »Excalibur HD FPT« probe for extreme loads minimizes the risk in process analysis measurement technology and offers maximum long-term reliability.

Extreme chemical resistance                       

Long-term use without additional operation costs

Resistance to extreme temperatures / thermal shocks

High-quality materials ensure reliable long-term operation

The sapphire to metal sealing technique in conjunction with innovative production processes provide significant advantages over other sealing techniques. A high degree of chemical resistance and pressure resistance is assured by the use of superior materials such as gold coated metal sealing and sapphire windows. The compliance required to withstand extreme temperature cycling without additional flushing of the probe internal is ensured by the nitrogen pressurization and of the probe inner parts, beside the cost saving effect for low temperature applications.

A second barrier ensures highest safety. The risk of leakage is greatly reduced by this.

Special Product Advantages

Offers the highest level of security - in every situation

Due to the robust construction with metal sealing and sapphire window, the highest chemical resistance paired with pressure and temperature resistance is guaranteed at all times (compared to O-ring sealed probes). The second barrier on the side facing away from the process reliably prevents product escape and leakage even in extreme situations.


Reliable measurement results without additional operating costs

Even at extremely low temperatures, the use of lightguides and the nitrogen filling in the probe tube means that there is no need for an additional flushing of the iinside of the probe. This eliminates the installation and operating costs that would occur for creating and operating a continuous flush.


Constant measurement results for easy method transfer

Through the use of the latest manufacturing technologies such as electron beam welding and the use of high-precision optical components, we ensure that the FPT probes offer consistently high quality of the measurement results. In addition, a method transfer between individual measuring points is facilitated.

»Excalibur HD FPT«  with a wide range of applications

The »Excalibur HD FPT« is primarly used for applications where elastomer-sealed probes reach their limits. The toughest process conditions in terms of pressures (up to 250 bar) and temperatures (-30 / 400 ° C) or extreme chemical pollution (such as nitric acid in fertilizer production) can be reliably measured with the metal-sealed »Excalibur HD FPT«. 




Target application:

  • Reaction tracking and reaction endpoint determination in chemical plants where increased demands on temperature resistance and service life are required, e.g. in resin and adhesive production

  • Quality control of material flows in petrochemical plants where increased chemical resistance and temperature resistance is required (e.g. quality control of petroleum and petroleum derivatives)

  • Quality control of organic solvents where increased chemical resistance is required

Excalibur HD FPT - Standard Configuration

To find your ideal configuration for this product, please follow the "adjust configuration" button at the end of this table

Model series Excalibur HD FPT 26
Measuring principle TRANSMISSION
Transmission Average over the measuring range > 20%
Wavelengths for UV: 230 - 800 nm (opt. >260 nm) Vis: 350 - 2000 nm; NIR: 800 - 2500 nm
Minimum Immersion Depth 35 mm + Path Length
Length of Probe Barrel Without flange: 250, 450, 650 or 950 mm, with flange: depending on max. immersion depth, allow 50 mm space for flange
Connection Optimized for fibers with 600 µm, NA 0.22
Temperature Restrictions T max: secondary confinement 290 °C, optical connector 150 °C, Copex PMA 130 °C (85 °C for ATEX)
Additional Functions The FPT provides a safety barrier and inerting with shielding gas (unless internal flushing is selected)
Probe Barrel Not suitable for Swagelok
Temperature -190 °C to 400 °C
Pressure -1 bar to 300 bar
Delivery Optical immersion probe, user manual, customer technical drawing, certificate of the pressure test, report of optical transmission test, transport packaging
Expected delivery time on request
Article number PX5_
Price per unit on request
Quantity 1

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Optical Probes and Flow Cells Configurator

Hellma offers the largest selection of products worldwide and the highest level of expertise to support your online measurements from UV to IR. Find the right measuring interface quickly and easily or configure your individual immersion probe or measurement cell.

Products of the brand:

Excalibur = Transmission

HD = Heavy duty

HY = Hygienic/3-A

XP = Xtremely precise

Excalibur HD FPT (Datasheet EN)



Hellma USA Inc.
120 Terminal Drive
11803 Plainview, NY
United States

Phone: +1 5169 3908 88


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