Is the measurement accuracy consistent for electromagnetic flowmeters of different diameters but the same precision?
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Two Yokogawa electromagnetic flowmeters with the same precision: one with a large diameter (DN200, measurement range 11–1100) and one with a small diameter (DN80, measurement range 1.8–180). When used to measure flow rates at 100, is there any difference between these two flow meters in terms of the discrepancy between their measured values and the true value? In other words, is it more accurate to use the one with a higher reading or the one with a lower reading?
Accuracy is relative to the range; the larger the range, the greater the absolute error.
I asked the manufacturer, and for flow meters, their accuracy is determined based on the current flow value, right?
In other words, there’s no need to choose a larger caliber. Theoretically, smaller is definitely better
Why? If the two instruments have the same accuracy level, it depends on whether their precision is described in terms of relative error or reference error. The accuracy of flow meters is described in terms of relative error (as stated by Emerson, the manufacturer of flow meters).
The flow meter manufacturers state that, aside from price considerations, two meters with the same accuracy level will yield identical measurement results.
Instrument errors are generally divided into two types: 1. Relative accuracy, which is usually expressed as a percentage; this refers to the accuracy relative to the full range of the instrument. In other words, the instrument’s accuracy is given as range x%, and the larger the range, the lower the accuracy. 2. Another one is the absolute accuracy, that is, the resolution of the instrument. This generally has nothing to do with the range. One of them is the answer you need.
It must be that smaller diameters offer higher precision; otherwise, why would there be a flow measurement range? Is this precision the accuracy within the measurement range? Otherwise, for those that measure on a 0-10 scale, such as the Yokogawa SE electromagnetic flowmeters, measurement starts from 0, and they offer relatively high accuracy for small-diameter pipes.
First of all, the discussion is based on the premise that all measurements are taken within the range provided by the flow meter! Outside the given measurement range, the accuracy of the flow meter definitely changes significantly. I just consulted the after-sales service of the Yokogawa flow meter manufacturer again, and they said that as long as it is within the measurement range they specify, the diameter has no significant impact. Also, the measurement range of the electromagnetic flowmeter is 1-100, right? .
Based on full scale, the larger the diameter, the greater the error