Answer / nandan

The principle is that analyzer supplies a negative voltage
to transducer,who converts it into a frequency & sends it
across the probe.Now as the probe comes into the area of
rotor it creates a magnetic field & with it eddy current is
produced on the rotor side.Which changes the amplitude of
the frequency.It induces the voltage & remaining frequency
comes to the transducer through the return way.Transducer
converts it into the voltage .
Now coming back to the question The gap voltage has a
negative relation with the voltage induced i.e. as the gap
increases the induced voltage decreases.So to make it to
into a linear relation ship, negative voltage is supplied.
i.e

Gap Gap voltage
0 mm 0 vtg
1 mm -9 voltage
2 mm 18 voltage
& when the probe is in air it will have no induced voltage
so all -24 voltage without induced voltage will return back.

Answer / jigaranadkat

Because it has PNP transistor inside which requires base
bias of negative (-ve) supply.

Answer / darpan

The principle is that analyzer supplies a negative voltage
to transducer,who converts it into a frequency & sends it
across the probe.Now as the probe comes into the area of
rotor it creates a magnetic field & with it eddy current is
produced on the rotor side.Which changes the amplitude of
the frequency.It induces the voltage & remaining frequency
comes to the transducer through the return way.Transducer
converts it into the voltage .
Now coming back to the question The gap voltage has a
negative relation with the voltage induced i.e. as the gap
increases the induced voltage decreases.So to make it to
into a linear relation ship, negative voltage is supplied.
i.e

Gap Gap voltage
0 mm 0 vtg
1 mm -9 voltage
2 mm 18 voltage
& when the probe is in air it will have no induced voltage
so all -24 voltage without induced voltage will return bac

Answer / mohammed abbas

Because it is NPN tansistor during the initail days when
this was inveted by bently the cost of NPN transiator was
less. then they started use NPN transiator for the
vibration propbe, due to this we will give negative 24vdc
supply

Answer / shankar rao

negative feed back required.

Answer / sai kiran.c

does really negative voltage exists......???

What is duty of as-built engineer.

2 Answers   Sofcon,

In RTU Panel we are having several Analogue & Digital Inputs /Outputs. We are recently facing some problems over Analog inputs , which are not updating properly (But Digital Input are updating normally) Can any one tell me from where the problem is creating , we have checked PLC CPU card, Analog Input card & we reconfigured ,But still the issue is there. Issue : 1. Sometimes Analog values are updating & sometimes not. 2. Analog values are not updating normally , showing some wrong Values 3. Total dead (0 value) Analog values are Level & flow measurement from the field instruments. (But in field the instruments are working normally & Displaying the values normally in local display unit) This problem we are facing in our Water Plant. If any one experienced this same problem or having any ideas related to our issue PLS send your valuable Answers/Replies...

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1 Answers  

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Do you have reference list?

0 Answers  

how to measure level under ground tank ? which type of transmitter very accuracy ?

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3 Answers  

What is two wire system and how it work

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2 Answers  

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0 Answers  

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0 Answers