Electromagnetic Transmittance Rate of Glass or Glazing
A proposed new ASTM International standard will be helpful in selecting glass or glazing that has a proper communication transmittance rate for the location in which it is being used. WK41897, Test Method for EMI Transmittance and Shielding Rating for Glazing Infill, is being developed by Subcommittee F12.10 on Systems Products and Services, part of ASTM International Committee F12 on Security Systems and Equipment.
Julia Schimmelpenningh, global architectural applications manager, Eastman Chemical Co., and an F12 member, explains that information can move through glass or glazing with varying degrees of effectiveness, depending on the electromagnetic transmittance level of the glass or glazing. In some cases, such as for cell phone reception or automatic payment systems for a toll road, a high transmittance rate is desired. In other scenarios, for example, in homes, offices and government buildings in which sensitive personal information is housed, a low transmittance rating is preferable.
"It has been determined that there is a significant need and desire to create a standardized methodology for acquiring an electromagnetic interference rating for glazing so that components of the glazing system could be selected based on a level and accepted playing field," says Schimmelpenningh.
The proposed standard will provide a test method by which lites or glazings can be evaluated for their transmittance on, or shielding capability to, electromagnetic frequencies. Use of the test method will generate data for glazing infill that can be used by consumers, designers and system manufacturers to understand the capability and contribution of glazing materials to EMI security systems.
"We anticipate that once it has been approved, the proposed standard will be used as a mechanism to aid in the selection of glazing infill materials for the production of windows, doors, skylights, cars, planes, boats and more," says Schimmelpenningh.
All interested parties are invited to join in the standards developing activities of F12. In addition to WK41897, work is being done in the areas of physical barriers, blast resistance, forced entry and locking mechanisms, among others.
CONTACT Technical Information: Julia Schimmelpenningh, Eastman Chemical Co. • Springfield, Mass. • Phone: 413-730-3413 | ASTM Staff: Joseph Hugo • Phone: 610-832-9740 | Upcoming Meeting: Oct. 21-23 • October Committee Week • Jacksonville, Fla.