Compact and robust measurement cell

For process reliability during measurements under harsh conditions

Excalibur HD Flange Measurement Cell

Compact Measurement Cell with Internationally Recognized CE-Certification in Accordance with the Pressure Equipment Directive (PED) For Industrial Process Analytical Technology (PAT)

Excalibur HD Flange

This optical flange measurement cell from Hellma consists of two optics which, combined with a central part, result in a flow cell. This compact measurement cell can be safely integrated into an existing system with little effort. The materials used are resistant to organic solvents and many acids and alkalis. Instead of elastomers, the cell uses patented metal seals with a high chemical and temperature stability.


Robustness and precision are combined in one product. This guarantees a long service life and best results. The Hellma measurement cell is the only one of its type with CE label, which means that it can be used in pressure vessels without acceptance. Measurement cells of this category are particularly suitable for transmission measurements under harsh process conditions.

Excalibur HD Flange Measurement Cell - For Industrial Process Analytical Technology (PAT)

Special product advantages

CE Label

  • Only measurement cell of this type with CE certification according to DGRL 2014/68/EU
  • Can be used in pressure vessels without acceptance
  • Operation in ATEX-zones 1, 2, 21, 22 possible
  • Periodic process and product TÜV audits
  • Very robust design, optimal heat protection of optics and light guides
  • Maximum safety for employees and plant - no accidental opening possible due to the firmly welded design


Simple installation

  • Very compact design
  • Space-saving installation in pipe systems
  • Flanges up to DN100 possible – well suited for large media flows


High precision and simple method transfer

  • Extremly precise path length accuracy through fixed set-up without spacers 
  • No accidental adjustments of the path length possible
  • Very high measurement accuracy simplifies method development and method transfer 

Measuring gap of the Excalibur HD Flange

Unique measurement head

  • Best Hellma quality and very high transmission
  • Robust metal sealings instead of elastomere sealings
  • Firmly welded sapphire optics instead of screwed optics
  • Extremely high chemical, thermical and mechanical resistance
  • No wear parts, maintenance-free and very long service time

Typical Applications 

  • Identification of educts, monitoring the quality of raw materials
  • Controlling the mixing ratio and the homogenity of major constituents in mixtures
  • Monitoring chemical reactions in tube reactors
  • Controlling chemical reactions in the bypass or at the exit of the reactor
  • Spectroscopic online measurement in oil production

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 HD Flange Measurement Cell (Brochure EN)


CE Certification according to DGRL module 2A (Certificate EN)



Hellma USA Inc.
80 Skyline Drive
11803 Plainview, NY
United States

Phone: +1 5169 3908 88


Disabled, please use email.