Answer / mohd

when the shaft moves toward the probe ,the gap vpltage will
change and that will be reflect on the negative voltage .
the main idea of using -10Vdc is to avoid interfering with
the noise signal which could give error in the reading .

Answer / dharmendra borada

Dears,
Bently Nevada Probes having Supply of -24VDC Supply because of NPN Transister used, so Sensor has to work between 0 to -24 VDC Range.
if u see the Graph of it's Vibration charesteristics it will be Linear Between -2 VDC to -22 VDC range & Vibration belongs towards &/or away from the probe.
and we can't say Vibration of M/C will be in which direction happens.
So it is Better to select middle point of it's Range as we can't assume Vibration Direction.
That's y Average/Middle point of Linear Graph range(-2 VDC to -22VDC) is -10 VDC(to Give Justice to Probe.
That's the reason of -10VDC Gap Setting needed.
Dear's this is the Answer according to my Knowledge.

Thanks in Advance.

Regards,
Dharmendra Borad

Answer / sudhansu

Bentil naveda vibration senser works on proximity principle of eady current type.so as the manufacturer define it as npn transister type so we got a negative proportional voltage with respect to gap generated.
so -ve output is due to -1)eady current and 2) for npn transistor.

Answer / manishahir

-ve for npn transistor and 10 for both side measure vibration ie towards the probe and opposite side of probe.so its change -10 to -24 and -10 to 0.

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