i want the equation of this question.
Tranmitter range is 120 mmwc and dcs flow range is 1700 nm3/hr. if i want to change dcs range from 1700 to 2400 nm3/hr then how much dp i have to enter in transmitter

Answers were Sorted based on User's Feedback



i want the equation of this question. Tranmitter range is 120 mmwc and dcs flow range is 1700 nm3/h..

Answer / carl_ellis

Answer: 239.2 mmH2O

Present max flow rate = 1700 nm3/hr
Present max DP (at max flow rate) = 120 mm H2O

New max flow rate = 2400 nm3/hr
New max DP (at new max flow rate) = x

2400/1700 = 1.412 or an increase of 141.2% in flow rate.

The DP and the flow rate relationship is a square root relationship, but the calculation is based on normalized percentage.

X = 1.412^2*120
X = 1.993*120
X = 239.2 mmH2O

The increase in max DP from 120 to 239.2 mmH2O is an increase of
239.2/120 = 1.993 or 199.3% increase in max DP at max flow rate.

Sq root of 1.993 = 1.412 or 141.2% increase in max flow rate (2400/1700)

Carl Ellis
Measure First

Is This Answer Correct ?    13 Yes 0 No

i want the equation of this question. Tranmitter range is 120 mmwc and dcs flow range is 1700 nm3/h..

Answer / alim

I think the equation is not straight forward, you need some repetition formula for calculating this.

Normally, I will use some software to do this kind of calculation such as InstruCalc. The data that you presented in the question is not enough. I am assuming that you are using the orifice in as the flow element, then you still need viscosity and specific gravity of the fluid.

Is This Answer Correct ?    1 Yes 1 No

Post New Answer

More Instrumentation Interview Questions

describe yourself?

1 Answers   TCS,


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

11 Answers   L&T,


Why we are measuring 4-20ma? Why we are not taking 0-20ma? Plz answer this

1 Answers  


what is the different between deflection type measurement and null type measurement in RTD?

0 Answers   SHR Solutions,


While preparing the graphic diagrams trend display, 3 types of trends are prepared by Yokogawa system vender. These are for process variable, manipulated variable & set point variable. Why these 3 trends are required? Explain the purpose of these 3 trends.

1 Answers  






HELLO FRIENDS PLZ EXPLAINE ME WHAT IS ORIFICE?AND HOW WE ARE USING IT IN INSTRUMENTATION

5 Answers   Wartsila,


installation process of orifice,a question asked for confusion creation in interview by BARC 1.if orifice is tightly fitted with pipe ,it will act like venturi 2.if orifice is left hanging in between liquid it will not create the pressure difference exactly,

0 Answers   BARC,


A PLC is programmed to drive three motors A, B and C as follows : After running motor A for an hour, motor B should get ON and motor A should get OFF. And after running motor B for an hour, motor C should get ON and motor B should get OFF. And after running motor C for an hour, motor A should get ON and motor C should get OFF. (That is, a cyclic repetition with time period one hour) Now, the second condition is: If any motor gone faulty and is tripped, the consecutive motor should get ON and the faulty (tripped) motor should be eliminated from cyclic repetition. The remaining two motors should bear the cyclic repetition of one hour each. (For healthy motor take logic as high and for tripped motor take logic as low) Now, the third condition is: When motor A load(Amps) exceeds 60% of its rated load, motor B should get ON in parallel to motor A. And when both motors A & B are running in parallel, and if their load exceeds 60% of their rated load, motor C should also start in parallel to A & B. [Here the cyclic repetition is eliminated, until their loads become normal(40%)] [Take logic high(1) for load at 60% and logic low(0) for load at 40%] Now draw a flow chart or a ladder diagram to fulfill the above condition.

0 Answers   MNC,


what is the difference between CPC and i/p converter

1 Answers   Siemens,


Close loop and open loop.

3 Answers   CCIE,


To calculate temperature, why we multiply 25 with mV?

2 Answers  


What is the input impedence of an OPAMP as an ideal device.

1 Answers   CCIE,


Categories
  • Civil Engineering Interview Questions Civil Engineering (5085)
  • Mechanical Engineering Interview Questions Mechanical Engineering (4451)
  • Electrical Engineering Interview Questions Electrical Engineering (16632)
  • Electronics Communications Interview Questions Electronics Communications (3918)
  • Chemical Engineering Interview Questions Chemical Engineering (1095)
  • Aeronautical Engineering Interview Questions Aeronautical Engineering (239)
  • Bio Engineering Interview Questions Bio Engineering (96)
  • Metallurgy Interview Questions Metallurgy (361)
  • Industrial Engineering Interview Questions Industrial Engineering (259)
  • Instrumentation Interview Questions Instrumentation (3014)
  • Automobile Engineering Interview Questions Automobile Engineering (332)
  • Mechatronics Engineering Interview Questions Mechatronics Engineering (97)
  • Marine Engineering Interview Questions Marine Engineering (124)
  • Power Plant Engineering Interview Questions Power Plant Engineering (172)
  • Textile Engineering Interview Questions Textile Engineering (575)
  • Production Engineering Interview Questions Production Engineering (25)
  • Satellite Systems Engineering Interview Questions Satellite Systems Engineering (106)
  • Engineering AllOther Interview Questions Engineering AllOther (1379)