I would like to ask how to use the calibration results of a flow meter
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This post was last edited by sailing0543 on 2019-10-25 at 14:30. It deals with one electromagnetic flowmeter, whose measurement range is 0–70 cubic meters per hour. The calibration result shows a precision of 0.6% FS, and the conclusion is that the flowmeter can be used as per these calibration results, as shown in the diagram. Since it is a flowmeter for wastewater discharge, environmental inspection requirements dictate that the flow rate should be adjusted according to the values specified in the calibration certificate. How should this calibration result be used for such adjustments? Our normal flow rate is 30 liters per hour. If the flow meter shows 30, the actual value should be 30 + 30*0.6%. Is this calculation correct?
I’m in sales, and I don’t quite understand this
Yes (30) +-(70*0.6%)
So within the required technical range, no further manual calibration is needed? It shows that the flow meter is working fine!
“The conclusion is “P”, so put a P there. . . Eat beans and peanuts; it’s fine to add a few more P’s as well. Every instrument has measurement errors; can those errors of the instrument be corrected? What about the corrections for those points within the range? By how much should the value be corrected? If instrument errors could be corrected, then why wouldn’t the instrument manufacturers correct them first before selling the instruments to you? Environmental Protection Bureau – I know a bit about it! . . . Let’s shame his ancestors. .
The calibration results show that this instrument is qualified and can be used further. The measurement standard is selected at a ratio of 1/3 to 1/10 of the criteria for determination; in other words, the expanded uncertainty or maximum allowable error of the measurement standard is 1/3 to 1/10 of the maximum allowable error of the instrument being tested. Under such conditions, the uncertainty of the measurement standard has a negligible impact on the uncertainty of the measurement results, meaning that the influence of the measurement standard on the results can be disregarded. Its citation error and repeatability calibration results are both good. When the uncertainty of the measurement result is less than or equal to 1/3 of that of the calibrated measuring instrument, there is no need to take the impact of measurement uncertainty into account during the conformity assessment; even if the measurement result falls in the marginal range, the probability of an incorrect judgment does not exceed 6% (when it is 1/3) or 0.5% (when it is 1/10). In such cases, there is no need to worry about the influence of measurement uncertainty.
If it is an electromagnetic flowmeter, then JJG 1033-2007 \"Specifications for the Calibration of Electromagnetic Flowmeters\" should be used; the details can be found clearly in that standard