Answer / jwg

For steam turbines, usually "relative vibration"
means "shaft relative [us. against bearing shell]
vibration" and "absolute vibration" concern bearing
pedestal vibration against free space, measured by seismic
transducer.
By combination of signals measured in one common axis by
shaft relative vibration transducer and bearing absolute
vibration transducer, "shaft absolute vibration" can be
calculated by electronic devices. In the past, "shaft
absolute vibration" was measured directly by sensors with
seismic system being in contact with rotating shaft surface.

Answer / ahmed

In general, the shaft absolute transducer system (which is
shaft vibration relative to space)consists of a relative
displacement sensor and a case-mounted vibration sensor
located in the same external housing. The displacement
sensor is a non-contact sensor measuring shaft position and
movement relative to the case, and the case-mounted
vibration sensor measures case absolute relative to free
space. The two sensors are phase compensated for the
different units and mathematically subtracted to get
absolute displacement of the shaft relative to free space.

Answer / mst

is there any phase angle in between relative shaft vibration and pedastal vibration. because in same phase it will addition. in out of phase it will subtract

Answer / hemant bhati

Relative Vibration in case of steam
turbines,compressors,motors etc. means we are directly
measuring the vibration by fixing the vibration probes on
the casing of Steam Turbine(ST) neglecting vibration of
case itself.
absolute Vibration will account Vibration of casing as well.

define COMPENSATION??

4 Answers   Bosch,

---

Air pressure in a pressure vessel can rise or fall at up to 2.5kpa/s.The pressure is sampled every 0.5 seconds.If range of the the pressure indication is 0 to 1500 kPa, what is the max value of the error due to sampling in % of Span

2 Answers  

---

can someone tell me about electronic speed switch &how it conect with proximittyswitch?(with dgm)

0 Answers  

---

why generation of syncronized generator increases when frequency of grid is less then 50Hz & generation decreases when grid frequency goes up from 50 Hz, as comparision with set value entered in govering panel?

1 Answers  

---

please send the sample qustion paper for iocl written test ..

0 Answers   IOCL,

---

what is the diffrence between mmwc and kg/cm2 for pressure measurment when we are using mmwc and when kg/cm2 and why????? ?? what is the reason

19 Answers   Ecoboard, Jindal, Sepco,

---

what is XV and KV valves?

4 Answers  

---

what is AWG?

2 Answers   NTPC,

---

What is the purpose of MATLAB?

3 Answers  

---

If a control valve is hunting means means if we are giving 50% to the cv, the cv will open at 51% then slowly slwoly it will reaches 49% , then it will reaches again 50%, this type of action occured frequntly.. so what to do for solve this problem. The possible cause is in volume booster or positioner's relay.. positioner is double acting .. and make siemens..sipart.The cv is double acting and mounted for anti surge operation, it having 4 nos. volume booster, one sov, one positioner, etc..?

2 Answers   Gujarat Fluorochemicals Limited (GFL), Shell,

---

what is the calibration standard for pressure and differential pressure transmitters?

1 Answers   Thermax,

---

what is the meaing of calibration curve?

3 Answers   HCL, Honeywell,

---