I have a question regarding instrument error: for a pressure of 5 MPa with an error of 1%, is the display value fluctuating or remains constant when conditions stay the same?
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I have a question regarding instrument error: for a pressure of 5 MPa with an error of 1%, does the displayed value fluctuate or remain constant when all other conditions stay the same? Is it fixed at 5.05 Mpa, or will it be 5.05 Mpa one moment and 4.95 Mpa another? There are also some questions regarding the concept of this error; please help clarify them. Thank you
Firstly, error is a static concept. It refers to the difference between the indicated value and the standard value when the measurement is stable; this difference is called error. An error of 1% means that the maximum error is no more than 1% of the full range. The error can be positive or negative; for instruments with a range of 0–5 MPa, the maximum error can be ±0.05 MPa.
“If the pressure is 5 MPa with a tolerance of 1%, and all other conditions remain unchanged, will the value fluctuate or remain constant? ” Answer: It is possible for the pressure reading to be fluctuating or fixed. For a pressure gauge with a precision of 1% and a range of 5 MPa, it is considered acceptable as long as the displayed value falls within the range of (5±0.05) MPa, and the drift over time is ≤0.025 MPa. Watches with poor time stability exhibit significant time drift when subjected to a constant pressure and tested for a short period of time. For example, when a pressure of 5.0000 MPa was applied for ten minutes, the reading on the gauge shifted from 5.01 MPa to 5.03 MPa.
“If the pressure is 5 MPa with a tolerance of 1%, and all other conditions remain unchanged, will the value fluctuate or remain constant? ” Answer: It is possible for the pressure reading to be fluctuating or fixed. For a pressure gauge with a precision of 1% and a range of 5 MPa, it is considered acceptable as long as the displayed value falls within the range of (5±0.05) MPa, and the drift over time is ≤0.025 MPa. Watches with poor time stability exhibit significant time drift when subjected to a constant pressure and tested for a short period of time. For example, when a pressure of 5.0000 MPa was applied for ten minutes, the reading on the gauge shifted from 5.01 MPa to 5.03 MPa.
If the pressure of the medium remains stable and the gauge reading stays constant, the error between this reading and the value shown by a gauge without any errors is within ±0.05 MPa.
Whether the display is fluctuating or remains constant under unchanged conditions depends on the stability of the instrument; if the instrument is stable, the display should remain constant, otherwise it will fluctuate. Error, on the other hand, refers to the difference between the measured value and the actual value, and it is calculated after measurement.
You have misunderstood the error. Error is the difference between the measured value and the standard value, and it is a static value. As long as the conditions of the pipeline remain unchanged, the measurement values stay the same.
Is this error fixed?
You are confusing errors with issues of measurement instability