What is the basic principle of vibration measurement by
BENTLY NEVADA vibration measurement system? and Why it
gives the -ve voltage output?

Answer Posted / sam

This is a very good, accurate writeup done by someone else
for a similar question earlier on. Hope it helps.


The vibration sensors used in turbine, generator etc are all
same type i.e proximity type of sensors. The sensor are
mounted at the proximity of the Turbine and generator rotor.
From the sensors one coaxial cable runs to the proximater,
which is mounted in a separate JB nearby. From TSI Monitors,
this Vibration probes gets +24 Volts DC. The proximater
gives a signal 0 to -22.4 Volts DC depending upon the
vibration measured by the sensor. Generally the distance
between the probe tip and the rotor is maintained such that
it gives -10 Volts DC when the turbine is not running.

The sensor works on eddy current principle. As the rotor
vibration increases, the eddy current generation remains
constant, but the absorption of power in terms of eddy
current increases. This loss of power is sensed by the
proximater and DC voltage signal is transmitter to TSI
monitor for Measurement, Controlling & Indication purpose.
Good luck

Is This Answer Correct ?    117 Yes 66 No



Post New Answer       View All Answers


Please Help Members By Posting Answers For Below Questions

Senior engineer's please help me, what is Loop Checking and Loop test? and write difference also? soon urgent

1617


how can use ram

1491


how do calibrate the valves.. with clear manual

1566


What is rang ability?

1801


Specify eight technical requirements that you would consider important, when deciding upon a particular control valve?

1438






what is different between 2,3&4 wire rtd and how much maximum distance using plc to field.

2292


if my flow is 20000 m3/h than which range of DPT i have to use????

1307


What is eddy current? Describe the operating principle of proximity probe.

1772


What are the error values can accepted in flow transmitter calibration?could u give any formula for this?

1415


I m appointed as an automation trainee engineer in small firm in that I am only the one , my company give me a project on s7-200 as i m beginner I don't know how to program so please send me the helpful site so that I complete my project before deadline....please help me out in this critical situation.

1578


whatis range of marcury filled tempereture gague

1505


how to connect transmitter measuring sulfur process? 1-by using long impulse line or 2- by using coated short impulse line

1590


I need to know steps to Calibration Valve Guard......

1001


where uses EXe /EXd/Exo/Exn/Exp/Exq/EXia

9345


how many maximum enter 2mm Dia solid cylindrical pipe into 8mm Dia hollow cylindrical pipe. give answer with calculation.

1586