Can a Flow Meter with Wide Scale Graduations Have Accurate Repeatability?

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In summary, the conversation is discussing the repeatability of a flow meter whose scale has graduations only 2 units apart. The question is whether this type of scale can have a legitimate advertised repeatability of 0.5% of the full scale. The instrument in question is able to return within 0.5% of the same spot for a given flow, regardless of the spacing of the scale lines. However, the issue of how a user can determine the repeatability when the scale lines are not fine enough is also raised.
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rollingstein
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Can a flow meter whose scale has graduations only 2 units apart (e.g. 90,92,94,96,98,100) have a legitimate advertised repeatablity of 0.5% of the Full Scale?

The scale runs 0 to 100 so that'd mean readings repeatable within 0.5%. When marks itself are 2 units apart how does this make sense?

In particular, I was referring to this instrument:

http://www.omega.com/Green/pdf/FL1500.pdf
 
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That means that for a given flow, the bob will always return to within .5% the same spot every time. Not sure how the spacing of the scale lines could possibly effect that.
 
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Integral said:
That means that for a given flow, the bob will always return to within .5% the same spot every time. Not sure how the spacing of the scale lines could possibly effect that.

In the sense, if you do not have a fine enough spacing of scale lines how do you know it returned to the same spot or how close to the same spot.

I guess an external mark, but to a user of the instrument isn't any repeatablity less than the minimum scale graduation a lost metric. How can he use it?
 

1. What is repeatability of a flowmeter?

Repeatability of a flowmeter refers to the ability of the instrument to provide consistent and accurate measurements when the same conditions are repeated. It is a measure of the precision of the flowmeter.

2. How is repeatability different from accuracy?

While repeatability measures the consistency of measurements, accuracy refers to how close the measured values are to the true value. A flowmeter can have good repeatability but poor accuracy if it consistently measures the wrong value.

3. What factors can affect the repeatability of a flowmeter?

There are several factors that can impact the repeatability of a flowmeter, including changes in temperature, pressure, viscosity, and flow rate. Additionally, the condition and calibration of the flowmeter can also affect its repeatability.

4. How is repeatability calculated for a flowmeter?

Repeatability is typically calculated by taking multiple measurements under the same conditions and then calculating the standard deviation of these measurements. A lower standard deviation indicates better repeatability.

5. Why is repeatability important for flowmeter measurements?

Repeatability is important because it ensures consistent and reliable measurements over time. This is crucial in scientific experiments and industrial processes where precise and accurate flow measurements are necessary for quality control and data analysis.

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