IBM Puts Sound to the Test
Posted July 6, 1998 7:00 a.m. EDT
RESEARCH TRIANGLE PARK — You've probably heard the announcement on airplanes: "Turn off your laptop computers and other electronic devices." The reason is that radio frequency can leak from improperly shielded electronics, interfering with the plane's electronics. WRAL OnLine reporter Tom Lawrence visited a unique room at IBM to see how they test their equipment for radio frequency, or RF emissions.
Four big chambers sit inside buildings at IBM. The shielded chambers allow engineers to test equipment for emission of high and low radio frequencies.
"We want to make sure that we don't interfere with cellular phones," says test engineer Dr. Bruce Archambeault. "We don't interfere with emergency broadcast services such as EMTs and fire and police and so forth."
Tests are run in another chamber to make sure equipment is protected from outside sources of RF. Dr. Archambeault says low levels of RF can affect equipment, but not humans.
"At the levels we're talking about coming out of a personal computer, now, there's no where near the amount of energy to be hazardous at all."
IBM has another chamber on its site where it tests the quietness of its products... and it's one of the quietest places on earth.
The acoustic chamber is suspended, double walled and thick fiberglass panels absorb sound. Acoustic engineer Dr. Ron Underwood says equipment being tested sits surrounded by sensitive microphones on a rotating boom.
"The microphones are rotating around and producing a measurement surface around the product from which we're able to rate the total acoustic energy that's coming out from the product."
To measure how loud something is, Dr. Underwood says you must do it in a very quiet place like this.
"The room is quiet or quieter than the audibility threshold of the human listener. So it is extremely quiet, one of the quietest places on earth."
IBM says it tests computers and other equipment to satisfy consumers demands, industry standards and federal law.