Q1: Consider part of a control loop, which excludes the transmitter, consisti

Q1: Consider part of a control loop, which excludes the
transmitter, consisting of a process, a controller and a
control valve which may be represented by two dead times of
0.5 min each and three exponential lags of 0.8 min., 1.0
min. and 1.5 min. respectively.

We wish to express this system as an overall first order
plus dead time (FOPLD) model ie gain, time constant and
process dead time. (We will see later that this is often
done, to simplify controller tuning). For this exercise,
gain is considered to be 1.0.

(A) If the transmitter is a flow transmitter whose
behaviour can be described by a dead time of 0.2 min. and
an exponential lag of 0.5 min. in terms of the overall dead
time and overall first order lag how can the system
behaviour be approximated ?

Overall dead time =
Overall time constant =

(B) If the transmitter is a temperature transmitter with a
temperature sensor in a protecting well whose behaviour can
be described by a dead time of 0.7 min. and an exponential
lag of 15 min. how can the overall system behaviour be
approximated now?

Overall dead time =
Overall time constant =

Question Posted / khalid

0 Answers
1538 Views
I also Faced
E-Mail Answers

No Answer is Posted For this Question
Be the First to Post Answer

Post New Answer

More Instrumentation Interview Questions

Advantages of servers over normal desktop in PLC SCADA system

1 Answers InfoMedia,

hi i want sov loop cheak from consol to field the operater given status to sov still no change, but MR room to sov ok so whats a problem and alreasy cheak all conection ok ?

2 Answers

What is the use of keyphasor in turbine.

7 Answers Hindustan Zinc, R&D,

Lube oil pressure transmitter local it's showing 9.8 kg/cm2 but dcs side it's showing 9.26 like that what is the reason?

3 Answers Edac,

what is differences between singal acting and double action valve

1 Answers Carlo Gavazzi, Welspun,

what is sinking and sourcing....

2 Answers

What is basic of instrumentation

8 Answers

while i check zero check for dp flow transmitter some fluctuating came (0 to 458 kg/h) what is the reason?

0 Answers Petronas,

how to derive kg/cm2 to mmwc? complete derivation.

11 Answers L&T,

i need some objective type questions in instrumentation

0 Answers

whats the problem will arrise if we rotate the hosing screw of the differential pressure transmitter?

1 Answers

can we replace a pressure transmitter of range 0 to 25 Kg/cm2 by a Pressure transmitter of range 0 to 10 Kg/cm2 ?.. Will it affect 4 to 20 mA output signal which we will feed to the PLC.

9 Answers IOCL,

For more Instrumentation Interview Questions Click Here