The Joint Commission requires that x-ray exposure measurements be determined for commonly used projections in all radiographic suites. In order to provide this information, specially designed phantoms must be used. The American Association of Physicists in Medicine (AAPM) Report #31 recommends the use of four special phantoms for use in diagnostic x-rays. The Extrmity Diagnostic X-Ray Phantoms from Capintec conform to AAPM recommendations contained in Report #31, “Standardized Methods for Measuring Diagnostic X-Ray Exposure.” The same phantoms are also recommended in AAPM Report #60, "Instrumentation Requirements of Diagnostic Radiological Physicists." These phantoms weigh 10 lbs (4.5 kg) and consists of one 25cm x 25cm x 2 cm piece of high-purity alloy aluminum sandwiched between two sheets of 25cm x 25cm x 2.54 cm clear acrylic.