Answer / carl_ellis

how to calculate flow range in DP tx

A flow range is calculated for a primary flow element
according to design flow conditions. The result of the
calculation is a maximum flow rate at a given DP span.

The DP transmitter does not 'calculate flow'. The DP
transmitter is spanned to the value in the calculation.
The DP transmitter can extract the square root from the
normalized percentage of the DP. That square root value
can be assigned flow rate values in fieldbus transmitters.
Or the square root value can be assigned flow rate values by
the local indicator on the DP transmitter. But the square
root 4-20mA output is just a signal representing the span of
the flow rate. Flow rate values are assigned by scaling in
the receiver.

Carl Ellis
Measure First

How Control valve sizing is done?

3 Answers  

---

How can we say that accuracy of measurement increases by using 3 or 4 wire RTD? because for example: If resistance of RTD element is say r ohms and Resistance of the cable from transmitter to RTD is R ohms And if 4 wire RTD is used, ____._____________________ R ohms | |_____._____________________ R ohms / \ / r ohms \ \ | |______.__________________ R Ohms | |_______._________________ R ohms Then the actual resistance measured will be: Total = r + R/2 + R/2 = r +R Ohms Note: r+R instead of r ohms. hence error

2 Answers  

---

what is the difference between sensor and tranducers?

12 Answers  

---

what is burner management system?

2 Answers   Alstom,

---

how to callibrate a new i/p converter

7 Answers   TATA,

---

---

Instrumentation engineer please reply me,I am electrical engineer ,what is the future in instrumentation dept {presently working (P&ID) Design} for me,whether good future for me as instrumentation department.what side can i get job in future

3 Answers  

---

if we put any thermocouple on a table in a room without any connection,what temperature should it show.

3 Answers  

---

why metallic housing is provided of solenoid valve.

1 Answers   HPCL,

---

In case of Transmitter's(e.g.Ultrasonic Flow meter ) we have an normal practise of selction of upstream and downstream distance such as (20D and 5D ).can anyone please let me know whow to calculate "D" ?? i guess it refers to pipe thickness is t right ?

2 Answers  

---

a pressure transmitter with a range of 0 to 2500kpag has a specified accuracy of 0.5 % of span.It is to be calibrated using a comparison gauge to have an accuracy of 0.1% of span.The comparison gauge has a range of 0 to 3000kpag What is the accuracy ratio? is this ratio acceptable?

1 Answers  

---

what is the difference between CPC and i/p converter

1 Answers   Siemens,

---

what is the conductivity sensor output formula and what is the ph sensor output formula?

1 Answers  

---