Interview Questions Answers in Instrumentation, Biological Sciences AllOther

Questions / { giridharan }

Questions Answers Category Views Company eMail

cascade controller is feed back or feed forward or both

4 Instrumentation 8902

why t/c is connected parallel and what is the purpose of it

2 Instrumentation 5626

give me the formula for analog to digital converter and also d to a converter

ACC,

Instrumentation 2354

Answers / { giridharan }

Question { ABC, 18949 }

defination of plc

Answer

PLC STANDS FOR PROGRAMMABLE LOGIC CONTROLLER

IT IS A SOLID STATE DEVICE AND IT WORKS ON THE USER DEFINED
PROGRAM WITH THE FIELD INSTRUMENT OUTPUT IT HAS RELAYS...

Is This Answer Correct ?

1 Yes

0 No

Question { TCS, 42849 }

why 4 to 20 ma ,why not 0 to 20 or 3 to 15 or anything

Answer

in this question i would like to add up my ideas

actually this 4-20 ma is fixed because of the main purpose
linearity of its output we can check whether its dead or not .

Is This Answer Correct ?

13 Yes

7 No

Question { PSU, 27392 }

what is skin type thermocouple?
how it is installed?
what is the difference b/w thermocouple & skin type
thermocouple?
what is gounded & non-grounded thermocoplle?
what is the diff b/w these two?

Answer

i would like to add up one point that skin t/c is one which
never as a shield and is directly connected to the body to
measure temperature...

Is This Answer Correct ?

22 Yes

0 No

Question { Reliance, 20535 }

What is the differace between Volumatric flow meter and Mass
flow meter.

Answer

mass flowmeter
density= mass/volume

mass = density* volume

so it can be expressed as measurement of fluid volume and
density

the example are coroilis ,thermal flowmeter

the volumetric flow is area*velocity
so it has the various type
magnetic,vortex,turbine,ultrasonic....and positive
displacement ...

Is This Answer Correct ?

11 Yes

0 No

Question { Kentz, 10906 }

WHAT REASEAN USE TRANSMETER TWO WIRE & FOUR WIRE

Answer

mostly in industry of petrochemical we will use only 2 wire
in which power and signal

actually signal will be 4-20 ma

power will be only 24 v so as it will send and same will
recieve it.

Is This Answer Correct ?

9 Yes

2 No

Question { DuPont, 18240 }

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

Answer

dead weight tester is used for a general gauge calibration
only we can have for high and low pressure gauge.. so its
used for only calibration by industrial people ... for low
we will have water ..for high oil is used ...

Is This Answer Correct ?

0 Yes

8 No

Question { 12602 }

Why shield is not connected at both end.

Answer

shielding is first of all resist the melting of temperature ,
the temp to sense has to be inserted in high temp region

Is This Answer Correct ?

3 Yes

37 No

Question { 10157 }

Is there devices to convert mechanical energy/rotational
energy into electrical energy.......?
PLease suggest me....

Answer

generator which converts mechanical energy into electrical
energy...

Is This Answer Correct ?

25 Yes

1 No

Question { Exxon Mobil, 25714 }

what is meant by calibration

Answer

calibration is a technique which a other(reference)
instrument like txt
which are compared to std instrument or a master piece

Is This Answer Correct ?

5 Yes

2 No

Question { Exxon Mobil, 25714 }

what is meant by calibration

Answer

i would like to add up the measured value with true value

Is This Answer Correct ?

4 Yes

2 No

Question { HCL, 8082 }

what is the meaing of calibration curve?

Answer

calibration are generally done

e.g the txt. has 4 - 20 ma than first we will start from

4,8,12,16,20 ma during the upward increment of txt reading.
same when we will do the 20,16,12,8,4 ma the downward
decrement reading this process of linearity is checked twice
in upward and downward for the o/p of txt this is
calibration curve

Is This Answer Correct ?

3 Yes

3 No

Question { HLL, 7287 }

Green house gases absorb which radiations?

Answer

the correct answer is only ir rays not uv rays

Is This Answer Correct ?

6 Yes

0 No

Question { Samsung, 109682 }

What is loop checking ?

Answer

checking out whether the reading is coming to the connected txt.

intially d.c.s and field instrument are connected
simulator is used to give mA to txt. and corresponding
readin g is checked in d.c.s whether the o/p is compared
with mA

0- 100 kg 4mA for 0kg and 20mA for 100kg

Is This Answer Correct ?

19 Yes

6 No

Question { 16763 }

why the discharge pressure of ID fan showing negative at fan
running condition.(boiler operating condition.)

Answer

pressure always flow from high to low pressure .
furnace pressure is high and atmospheric pressure is low

when the damper is opened automatically all the pressure to
the low pressure. the low pressure in the sense it is vaccum
only and negative is only vaccum

Is This Answer Correct ?

4 Yes

10 No

Question { Reliance, 13616 }

what is the use of impulse line in AFBC boiler , WHY WE
CONNECT IMPULSE LINE TO TRANSMITTER , DRFT GAUGE ETC ????????

Answer

transmitter has a sensor which has a temperature withstand
around 150c but actually steam line is more than 500c this
txt. cant withstand so a condensate pot is available in txt.

impulse line are connected to that pot through that a cold
dm water is poured and txt. taken in line when steam comes
it gets condenses in that pot itself so sensor will not be
affected

Is This Answer Correct ?

13 Yes

0 No