Flow measurement range
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I have just purchased a DN100 electromagnetic flowmeter. The flow rate range indicated by the manufacturer is 10–100 M3/h. Why isn’t it 0–100 M3/h? Could you please advise?
0 to 10: dead zone, not displayed
0 to 10: dead zone, not displayed
0 to 10: dead zone, not displayed
Ask the manufacturer! Does 4MA correspond to 10 or 0? This is usually the case for rotors.
The flow rate is too low to be detected, but the transmitter output should still be 0, corresponding to 4 mA
(0~10) ~ (0-100) 4~20mA
How should one understand what you wrote? Please be more specific, thank you
Take a look at the table. It is the minimum and maximum measurable ranges.
For a flow rate range of at least 10 M3, it is possible to calibrate an output of 4–20 mA (9.9 is not acceptable); for a flow rate range of up to 100 M3, it is also possible to calibrate an output of 4–20 mA (101 is not acceptable)
Generally, flow meters are unable to measure low flow rates or exhibit very large errors, making the readings unreliable; hence the concept of range ratio exists. The range ratio for this flow meter is 1:10. For the configuration on the DCS side, it’s sufficient to use a range of 0 to 100. Note that the DCS should implement filtering for low flow rates (that is, when the flow rate is less than 10, it should be set to 0).