July 17, 2007

Stress waves ID faults before they derail production

“Machine failure,” says Marc Hunter, of Invensys global alliance marketing, “is a process, not an event.” He described the process using the unfolding of a car wreck event as an analogy. Traditional vibration monitoring devices, he said, start picking up problems at the grinding and gnashing stage, just before the wreck occurs. Stress wave analysis, on the other hand, can pick up problems far earlier in the failure cycle.

Invensys has partnered with SwanTech, a Curtiss-Wright company, to private label SwanTech’s patented stress wave analysis devices and systems and bring them into the company’s I/A and InFusion framework.

Stress wave analysis uses a passive piezoelectric sonar sensor to monitor ultrasonic energy emitted from rotating machinery. “It is the stethoscope,” Hunter said, “capable of ‘hearing’ friction when it first starts.” Up to eight sensors connect to a SwanGuard device, which does data reduction and sends the data, either wirelessly or over Ethernet or other connection to a SwanServer, a Linux-enabled webserver that does final data analysis and provides a bidirectional link, via OPC, to an I/A or InFusion system.