New generation of monitoring systems with on-line diagnostics

Experimental validation of non-contacting measurement method using LED-optical displacement sensors for vibration stress of small-bore piping

“…Among commonly used measurement methods of the vibration stress, one method estimates the vibration stress using strain gauges glued on the piping [8][9][10]. Another method calculates the vibration stress by identifying the vibration modes based on the results measured using a few accelerometers attached on the piping over a wide region [11][12][13]. These methods can provide accurate measurement but they need a lot of preliminary work such as installing the detectors and a good level of skill to interpret the results.…”

A Method Using Optical Contactless Displacement Sensors to Measure Vibration Stress of Small-Bore Piping

“…The following methods are generally used to measure the vibration stress generated in piping systems: methods to estimate the vibration stress by substituting the measured values into evaluation equations where the equations are derived from approximation of piping as a simple geometry and the measured values are obtained by portable vibrometers [15]; methods to measure the vibration stress with strain gauges mounted on the piping [16][17][18][19]; and methods to estimate the vibration stress by using vibration modes identified from the acceleration measured with many accelerometers installed throughout the piping systems [20,21]. The following vibration measurement techniques for structures and equipment including piping are also being researched at present: laser techniques based on interference and Doppler effect of light [22][23][24][25][26][27][28][29][30][31]; vibration sensors based on optical fiber and piezoelectric devices [32][33][34][35][36][37]; and techniques using laser displacement sensors [38,39].…”