Usually, those prefailure symptoms include a change in the vibrations the machine gives off. Until now, vibration monitoring and analysis was too costly for most equipment. Engineers at Analog Devices, Norwood, Mass. (analog.com), however, have brought the price down with their ADXL001 high-bandwidth MEMS vibration sensor. Unlike other sensors that detect vibrations from 0 to 5 kHz, the ADXL001 covers all the way up to 22 kHz. This lets factory managers identify failing equipment long before damage is done.
The device comes in a 5 5-mm ceramic eight-pin package that is hermetically sealed against dust, dirt, and humidity. It can be ordered with one of three full-scale dynamic ranges, ±70 g, ±250 g, and ±500 g. Nonlinearity is 0.2% of full range. The sensor is said to be highly resistant to EMI/RFI, and operates in temperatures from –40 to 125°C. The device is powered by 3.3 to 5 V. Cost is $35 in quantities of 1,000.
The mechanical sensor on the vibrationsensing chip is shown under acceleration.