결함 있는 중국 건식 벽체의 신속한 비파괴 선별

Reports of safety issues and property loss from the use of imported Chinese drywall have proliferated the news. Liability is being argued in the courtrooms while owners of property constructed and repaired with these material are dealing with its consequences. Corrosion of metal piping and electrical work, foul odors, blackening of walls, and other serious problems are among the issues. Drywall is manufactured from gypsum (calcium sulfate); and, while it is still not absolutely certain, current research indicates that the problems arise from the release of certain sulfide gases. It is believed that elevated levels of Strontium (Sr) are indicative of the defective, imported drywall from China. An inter-agency task force is developing standard federal testing protocol to identify defective Chinese Drywall.1

Handheld XRF's are used to test drywall quickly and easily without moving or destroying it. Drywall Detectors, LLC2 use Handheld XRF to compare levels of Strontium (Sr) and Sulfur (S) in domestic and imported drywall. They reported results for domestic (gray) drywall at levels less than 1,000 ppm for Strontium and at levels less than 1% for Sulfur; while defective Chinese drywall (blue) had elevated levels of Strontium at levels greater than 2,000 ppm and Sulfur with levels at or greater than 2%. Our Handheld XRF can measure up to 25 elements in a single test, including Sr, S, Fe, Ag, Cu and more.

XRF Testing of Drywall is Simple, Fast and Non-Destructive

Drywall Detectors tested intact drywall, defined as drywall that has undisturbed paper, intact on both sides. Essentially, it is tested as it was manufactured. For accuracy, they recommend testing a one square inch patch clear of paint and/or wallpaper. In most cases vent covers, outlets, attics and other unfinished areas provide testable drywall paper; however, in cases where they are not, the patch can be cleaned by scrapping, sanding or wire brushing.

1. Executive Summary, November 2009
2. www.drywalldetectors.com, Baltimore MD