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

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

Question Posted / ssraosgapipl

2 Answers
12955 Views
GMR, I also Faced
E-Mail Answers

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

what is the T/C & RTD mesuremaint?

3 Answers

Why only negative 24 vdc supply give in vibration measuring system.

6 Answers

Why do we use triad cable for RTD to Temp.transmitter connection? Why we don't use 3 core cable?

1 Answers Process Control Technologies,

Q- Why Phase tester is only used for checking AC not DC ?

1 Answers

why would you like to join our company

0 Answers Aramco,

What is the difference between precision and repeatability of any instrument. Why it is measured always in percentage

2 Answers

If fire would be inside the plant which fire detector is to detected the fire.

0 Answers KOC,

Why is the length of cable layyed from RTD to temp. Transmitter should be minimum? Why does heating effect takes place in their?

1 Answers Process Control Technologies,

temptrure me ketne frequiency hote hai

0 Answers ME,

why used three wire in RTD.

8 Answers BARC,

Is Hart communicator calibration device or communicating device for transmitter?

4 Answers Yokogawa,

Displace type LT to be calibrated in workshop, wt. 40, dia- 60 mm, density- 0.8kg/cm3.

0 Answers CCIE,

For more Instrumentation Interview Questions Click Here