Rhopoint Instruments partnered with the materials department of ETH University in Zurich to develop the Rhopoint ID, which provides a new and innovative way to measure transparent appearance of materials and correlates to customer perception. The patented measurement technique quantifies the see‐through qualities of materials and offers the ability to measures small sample sizes and curved surfaces that cannot be measured with a traditional haze meter.

A backlit, high accuracy reference target graticule functions as the viewed object, creating a highly defined pattern of light intensities with optimally sharp transitions between the backlit and masked areas. The camera works like the human eye quantifying changes in the transmission of the light caused by a test material. Image analysis techniques are used to characterize these effects into parameters, which correlate closely with human perceptions.

The Rhopoint ID measures the following:
Haze: Quantifies the loss of contrast for objects viewed through a material, measured directly by evaluating contrast of the black and white areas on the graticule. Measurements made with the Rhopoint ID are fully comparable with those made on an ASTM D1003 haze meter.
Sharpness: Quantifies the loss of perceived detail for objects viewed through a material. When viewed through a material with high sharpness, an object appears sharp and distinct. As material sharpness decreases, the object appears blurry and obscured.
Distance Dependency (Haze & Sharpness): Many materials exhibit a variation of transparency depending on whether the material is in contact with a viewed object or separated by an ‘air gap’ distance between them. This metric can reportedly only be measured with the Rhopoint ID.
Rhopoint ID benefits compared to a traditional ASTM D1003 Haze meter:

  • The ability to measure small samples that cannot be measured with a traditional hazemeter.
  • The Rhopoint ID can measure samples down to 6mm x 2mm* which makes it ideally suited to applications such as blister packaging.*
  • The Rhopoint ID is also able to measure curved surfaces which makes it the first instrument of its kind that can be used by the PET bottle industry.
  • Its fully sealed design provides a safe and accurate way of measuring liquids without the fear of damaging the instrument.
  • The Rhopoint ID can be configured to replicate the final use application of a material, from "material in contact" to a 40mm gap between the test sample and a viewed object. This method allows optical performance to be assessed using real world conditions.
  • Utilizing the ‘live view’ camera function of the software, areas of interest can easily be identified and the sample positioned for measurement very quickly.
  • Requires Rhopoint ID‐L version, which includes analysis software. Multiple instruments can be installed and connected to a LAN and ID software is free to install on multiple computers so any computer can run and interrogate results from any instrument.

This new technology can be used by current users of ASTM D1003 haze meters or for any of the following applications in which the measurement of transparent appearance is important:

  • PET Bottles
  • Blown film
  • Food film
  • Medical films
  • Glass
  • Abraded materials
  • Privacy glass / films

For more information visit www.rhopointinstruments.com/product.