The ISO OPAL (Optical Properties Authorized Laboratory) group met at Monash University just outside of Melbourne, Australia November 14 & 15, 2019. The ISO TC6 (pulp, paper and paperboard) met the following week. This OPAL group is comprised of organizations which have been approved via ISO 4094 to provide optical calibration standards for ISO Standard 2469 conforming instruments. These are the labs that issue calibration standards for use within the Pulp & Paper Industry for the calibration of ISO 2469-conforming brightness, color, whiteness and fluorescence instruments. This ensures that paper makers, printers, pulp mills, chemical companies and other related organizations are using properly calibrated equipment which allows for setting specifications and meeting contractual obligations in buy-sell agreements.
The group meets in person at least every 18 months to review data and comparisons among each other. Also, procedures, issues and techniques are discussed with the group. The Chairperson of ISO TC 6 (Technical Committee on paper, pulp and paperboard) WG3 (Working Group on optical properties) leads the discussion. The group shares data, techniques and concerns on an ongoing basis as well. Current members include:
Technidyne Corporation (USA)
Each OPAL member produces and distributes IR3 standards for optical measurements according to ISO 2469 for the measurement of ISO 2470, 5631, 11475, 11476, and 22754 (and others). In order to maintain a high level of agreement among the labs, they participate in monthly inter-laboratory comparisons. This means the labs produce and ship standards to each of the other labs each month. They read the standards that were received and generate a series of tables showing the monthly comparisons of spectral reflectance (minimally 400-700 nm), fluorescent (UV Level D65 & C) and non-fluorescent levels. This data is then maintained on a common website for later analysis. This aids the labs in detecting differences or changes among the group. In regularly scheduled meetings (like the one in Melbourne), each lab reports and discusses any observed trends, changes or differences. This helps build a cohesive group for issuing standards. The idea is to provide the best agreement among customers that receive standards from any of the Authorized Labs. A new report will be issued by the OPAL in the near future which illustrates the inter-laboratory reproducibility. To learn more about Technidyne's calibration process and materials, contact Nick Riggs and see our Calibration Standards