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I have an orifice plate calculation which stating that the max DP as 125 mBar at max flow rate 500 m3/hr.
Accordingly i have calibrated the FT with 0 - 125 mBar and 500 m3/hr.I beleive in the DCS also i should set the range as 0 - 500 m3/hr.Surprisingly our engineering contratctor given the DCS range as 0 - 670 m3/hr.Is this right or not???
Not : My FT Transfer function set as Square root...
Expecting immediate responses.....
The DCS scale should be a linear 0-500m3/hr, with the square root extraction done in the transmitter.
if the flow rate is 0 to 500 m3/hr then the DCS range should be equal, otherwise the process measurement will be the same.
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DCS setting is wrong, must must be 500
[QUOTE=carl_e;264542]The DCS scale should be a linear 0-500m3/hr, with the square root extraction done in the transmitter.[/QUOTE]
square root calculation shall be performed in DCS.
[QUOTE=carl_e;264542]The DCS scale should be a linear 0-500m3/hr, with the square root extraction done in the transmitter.[/QUOTE]
square root calculation shall be performed in DCS.
[QUOTE=qdzung;279300]square root calculation shall be performed in DCS.[/QUOTE]
No. That's wrong. The original poster (OP) stated, "My FT Transfer function set as Square root". Go back and read it. So the flow transmitter is doing the square root function.
Hence, the answer to this thread's question relates to the conditions originally stated.
Maybe your plant has a policy that square root is done in the DCS. That's fine. Do it that way. But it does not relate to issue of a contractor providing the wrong range value for that point to the DCS.
[QUOTE=qdzung;279300]square root calculation shall be performed in DCS.[/QUOTE]
No. That's wrong. The original poster (OP) stated, "My FT Transfer function set as Square root". Go back and read it. So the flow transmitter is doing the square root function.
Hence, the answer to this thread's question relates to the conditions originally stated.
Maybe your plant has a policy that square root is done in the DCS. That's fine. Do it that way. But it does not relate to issue of a contractor providing the wrong range value for that point to the DCS.
Dear Carl,
Thank you very much.
I wrote my comment because I familiar with other specifications.
Regarding the question from topic, the DCS engineer had made mistakes while input "System range" for this transmitter. The System range should be sam with Calibration range : 0-500 m3/hr. You should request DCS engineer to check this.
Dear Carl,
Thank you very much.
I wrote my comment because I familiar with other specifications.
Regarding the question from topic, the DCS engineer had made mistakes while input "System range" for this transmitter. The System range should be sam with Calibration range : 0-500 m3/hr. You should request DCS engineer to check this.