Volume 42, Issue 9 - September 2007

Codes & Regulations   

ASTM Standard Details Methods to be Used 
to Determine Index of Refraction

A new ASTM International standard describes a variety of methods that can be used to determine the index of refraction and dispersion of glass. The standard, C 1648, Guide for Choosing a Method for Determining the Index of Refraction and Dispersion of Glass, was designed for manufacturers of glass and glass products, as well as designers of products in which glass is a critical component. C 1648 was developed by subcommittee C14.11 on Optical Properties, part of ASTM International Committee C14 on Glass and Glass Products.

According to Herbert L. Hoover, a C14 member now retired from Corning Inc., knowledge of refractive index and dispersion is necessary for manufacturing glass for certain applications. “For example, the refractive indices and dispersions of optical glass are the basis for their selection for specific applications, such as telescopes, microscopes, lenses and prisms,” Hoover says.

Hoover adds that accuracy of values and ranges of wavelengths covered, as well as speed, cost and convenience, all must be considered when selecting a refraction measuring method. “C 1648 provides information on methods of measurement that will enable a prospective user to choose appropriately what method should be implemented,” Hoover says.

Descriptions of the following test methods are included in C 1648:

  • Becke line (method of central illumination);

  • Apparent depth of microscope focus (method of the Duc de Chaulnes);

  • Critical angle refractometers (Abbe type and Pulfrich type);

  • Metricon system;

  • Vee-block refractometers;

  • Prism spectrometer; and

  • Specular reflectance.

In addition, four other methods are briefly detailed in Annex A1. www.astm.org

ICC Seeks Funding for Building Departments
In an ongoing effort to obtain funding for a proposed Community Building Code Administration Grant Program, which would provide funds for local code enforcement, representatives from the International Code Council (ICC) have held more than 130 meetings with members of Congress.

The proposed grant program would provide money to municipalities during periods of building booms or following natural disasters to account for increased oversight of building codes through the hiring and training of inspectors.

“This grant program will help increase professionalism in order to better protect the public, especially during natural disasters,” Wally Bailey, ICC president and director of development and construction for the city of Fort Smith, Ark., told congressional representatives. In addition the U.S. Department of Housing and Urban Development (HUD) says the 2006 International Building Code (IBC) and the 2003 ICC/ANSI A117.1 Accessible and Usable Buildings and Facilities as Safe Harbors are in compliance with the federal Fair Housing Act (FHA) accessibility requirements. 

Architects, developers, builders and others, such as contract glaziers, who use the 2006 IBC to design and construct multi-family housing are in compliance with the FHA. www.iccsafe.org

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