Question { Reliance, 14640 }

Describe how to calibrate various types of instruments and
transmitters using ISA industrial consensus standard
techniques.

Answer

Calibration Can be Carried out By Calibration Instruments
such As For Pressure Transmitter,level transmitter the
pressure pumps with mA in Series or Can be used simply
HEART with a Pressure pump,By increasing the pump pressure
the master guage shows the indication of the Standared
pressure Corresponing to which mA reading canbe Obtained
check for incrasing and decreasing Valus for 4,8,12,16mA If
Error Occurs then Set a Zero or Span Adjustment,Simillarly
For RTD,T/C in Furnace is Carried out.

Question { DuPont, 19075 }

what is dead weight tester and where it is used?.

Answer

Dead Weight Tester Is A Instrument Used to Caliberate the
Pressure Guage,Pressure Transmitters, Pressure Switchs,It
Is A industry Based Applicaion Instument.

Question { Schneider, 7323 }

What the basic of communication?

Answer

EXCHANE OF INFORMATION BETWEEN TWO MEDIA OR BODIES IS TERMED
AS COMMUNICATION
for communication we need 1) signal 2) address and 3)means
of transport of signal like cable, wireless

Question { Siemens, 6046 }

suppose there is gas flow meter I want to know weather
meter calibration is done at high pressure or low pressure?
pls justify.

Answer

Meter Caliberation Is Done at Low Pressure,Because At low
pressure range We get high Accuracy,High Resolution which
helps for Detection of Deviation Quickly and Can Be
Caliberated Quickly by Fine Tuning.

Question { 7642 }

explain level transmitter working

Answer

level transmiter(DP transmiter) Consists of a pizoelectric
material which is a resistive material i.e as the pressure
is applied on it the change in dimension takes place, this
application is used in level measurement differential
pressure is applied,from upper tapping point to the
transmition, this end called High tapping point at the
transmitter which is maintained at high pressure so that at
low tapping point will cause changes as the change in level
occurs this level acts as pressure on pizoelectric material
so this causes change in dimension of material which is
electriacally converted into mA by Bridge and transmitted
to the control room.

Question { KNPC, 5607 }

Consider a level troll.
i am getting a correct value in 4mA and 20mA.
the value in the middle(30 to 60%)is disturbed and i am not
getting the appropriate value.
what is the solution to normalize the level and to get the
correct value..

Answer

Just Simply Calibrate the transmitter With Different ranges
check for

0% should get 4mA
25% should get 8mA
50% should get 12mA
75% should get 16mA
100% should get 20mA
take reading from Increasing and decreasing Reading. And
According to which plz Set ZERO or SPAN.

Question { 9415 }

how to measure temperature from resistance of rtd?and how to
measure temp from voltage of thermocouple?is there any formulas?

Answer

Temperature measurement.

With RTD:
The Material used Is Platinum Which is very Sensitive to
the temperature as the temperature Changes the Resistance
changes.Which is next connected to form a Weatstone bridge
in the transmitter then According to the formula
R1/R2=R3/R4 since R2,R3,R4 are Constant So Change in RTD
Resistance R1 The Corresponding mA Signal is Obtained
through the transmitter to the system in control room.

With T/C:
Were As T/C is the Formation of two diffrent Material
Combined to form a T/C(SEEBACK EFFECT)As they r two
different materials Change in temperature Causes the change
in EMF generation between the two materials,This mV Signal
is then Transmitted to Marshelling cabinet to Convert it
into V because all Digital Signal read minimum 5V,it is
Converted by OP-Amp with 250ohm Resistance Across it whict
is convinient to DCS to read it.

Question { Qatar Petroleums, 11171 }

what is load line in control valve?

Answer

As Due To Change In Flow If it Is Terbulent flow, Cavitation and Flashing Occurs due to whoch Load Ocurs on the Control Valve.