PORTLAND, Ore. The world's first micro-electro-mechanical system (MEMS) accelerometer technology capable of tracking vibrations in industrial equipment at frequencies as high as 22-kilohertz (kHz) debuts today at the Sensors + Test Conference (May 6-8, 2008, Nuremberg, Germany). Created by Analog Devices Inc. (Norwood, Mass.), the MEMS technology uses unique differential accelerometers--two side-by-side MEMS mechanisms capable of cancelling out common mode noise. ADI's vibration and shock sensors are also small enough that equipment designers can build vibration=detection chips into industrial process-control devices, rather than as add-on modules.
Today, vibration sensors are piezo-electric-based modules that are limited to about 5-kHz frequencies and cannot be mass produced the way ADI uses CMOS processing lines to mass produce its accelerometers. As a result, according to ADI, it can undercut the price of piezo-electrics by 50 percent--$35 as opposed to $70.
"[ADI] is in the right place at the right time with the right product," said Marlene Bourne, chief analyst at Bourne Research (Scottsdale, Ariz.) "Manufacturers are looking for all the help they can get to improve production and equipment efficiency. While the industrial market is certainly small compared with consumer electronics (in terms of unit shipments), it's an incredibly important market revenue-wise; the margins are much better. This is because MEMS sensors are addressing identifiable needs within the industrial sector and, thus, providing tangible value."
Also, instead of bolting a piezo-electric module onto the side of a piece of vibrating industrial equipment, ADI's chip-based accelerometer sensor can be integrated right onto the circuit board of the device when it is manufactured. ADI expects that some piezo-electric module makers will retrofit their MEMS chips into existing bolt-on modules, but it also expects makers of industrial equipment to cut out the module maker and just integrate their MEMS chip into their motor, pump, gear box, or other piece of industrial equipment.
Vibration sensors are becoming increasingly popular on industrial manufacturing lines, because they can sense on-coming failure before they happen. For instance, a bearing going bad will vibrate at a high-frequency before it fails. And as it gets closer to failure, the frequency will drop until it finally burns out altogether, possibly damaging the rotor it is supposed to be protecting. For that reason, predictive maintenance is becoming increasingly popular.
"The current trend in industry today is to go beyond preventive maintenance, to predictive maintenance [PdM]," marketing manager Christophe Lemaire at ADI, said. "Predictive maintenance can lower the cost of repairs by more than 25 percent, if you can detect them early.
"It can cost ten times more to repair equipment if you have wait until it fails," said Harvey Weinberg, senior applications engineer at ADI.
According to Lindsay Engineering (Camarillo, Calif.), vibration analysis provides up to three-times more return-on-investment, when compared with other PdM techniques, such as infrared thermography or ultrasonic analysis.
ADI's family of differential vibration and shock sensors for industrial markets joins its family of iMEMS accelerometers for automotive and consumer applications. As with ADI's other iMEMS accelerometers, its vibration and shock sensors come in a ceramic package. They are available in 70g, 250g and 500g ranges.