Vibration Sensors - Insights

Direct output of 4-20mA for ancillary plant items.

Electronic have made the sensors smaller.

Microelectro mechanical systems MEM's

Metrix? Mainly using Bently Nevada, but their pricing has gone crazy since GE took over.

Bruel & Kjaer PCB freescale national semiconductors

Taiwan maybe is leading the vibratory sensor

I use Bently Nevada vibration sensors for monitoring and protection of steam turbines, compressors and other rotating machinery.

Vehicles - ride comfort. Engines - Satellites - Ground Vibration - Machinery, predictive maintenance

Characterization and measurement of vibration systems vibration test low frequency measurement

Machining of metal with large dept of cut can be study the minimum and maximum thickness of material use to absorb vibration.

What is "standard" or "non-standard"? The field of applications is huge.

Body Vibration measurement on elder people to react to a fall

A gas turbine which had only seismic sensors was destroy blade wheels and it was noticed by seismic sensor as moderate vibration. When some provisional proximity probes were installed the problem appeared clearly detected by the proximity probes as severe vibration.

Damaged cables by fitters unscrewing sensors without electrical disconnection, destroying cables. Loose metal ID labels being attached to sensors where they could vibrate on their own.

There was a train disaster caused by defective wheels, which I believe could have been avoided using vibration monitoring .

Practical product support. Bently Nevada have been pretty useless at supporting product when issues arise, in our case signals going open cct for unknown reasons. They will not assist with fault checking of suspect devices, only interested in selling new units. mA outputs to allow signals to be sent over extended distances without degrading or being influenced by surrounding plant. Reliable plug in system to allow for easy disconnection and high waterproof integrity. Plug and receptacle is suspected to be an issue for us with existing Bently Nevada's, but has been blamed on old monitors which may be the case also, but when we have replaced monitors in some cases the issues continued. Most issue occur when item is out of service, hence low real vibration environment. Suspect when in service plant vibration keeps contact viable through constant movement.

3-axis, time and frequency domain, active sleep mode with threshold interrupt possibly integrated in sturdy design

Configuration settings saved as icons ready for playback for various applications

Wide band High sensitivity Cross-sensitivity

Reduced size and lower power consumption

Its characteristics of work and prices

Integrated energy and datalogger

Self calibrating sensor

Size and portability

Improvements in EMC

Lower cost

Cableless

Insulation, isolation, segregation and high quality installation are critical. Avoid earth loops at all costs. Look hard at end use to establish the suitable level of technology for the application. Vibs are sold on what they are capable of doing in the hands of an expert and within expensive software and hardware systems. There seem to be few people out there who diagnose the results and give any practical advice on what actions to take on the results. Much of it seems to be record for the sake of recording, but when an issue arises, no-one is certain what actions should follow.

Understanding your machine, the process they carry on, and what you are monitoring and how you are doing it is essential and can save you a whole lot of money.

Carefully check the sampling rate and filtering of data acquisition compared to the resonant frequency of the sensor (to avoid aliasing).

Study something about them before buying, buy an calibrator or a regulated shaker so you may generate and really measure real vibrations.

Yes, only the people need to know the intervals in frequency and amplitude to measure

Be sure the mounting is ok and the shock wave can not damage the sensor

Spend attention on the DAQ system that follows the sensor

Better use the better sensor, not the cheaper one