For example, Coriolis mass flowmeters are only calibrated in mass flow units. Stipulations do exist, however, and the manufacturer should be consulted prior to specification of custom calibration.
As more points are chosen, the cost required to perform custom calibrations becomes more expensive. In fact, special calibration points and ranges are often specified on meters for critical applications. This does not mean a custom calibration could not be performed at unique points like low flow ranges. Q: What options exist in calibration related to flowmeters?Ī: Flow calibrations are performed at flowrates typical for the meter size and based on standard measurement points defined from a history of like meter calibrations. These factors include, but are not limited to, the accuracy or repeatability of the comparative standard used, calibration interval of the master standard, comparison procedure, unit conversion error, failure to perform field adjustments at reference conditions, failure to consider all error factors, or actual test meter drift or error outside of manufacturing tolerances.Ĭonsequently, the best recommendation is to consult with the manufacturer and ask for help or a re-certification at the calibration facility. Q: How do you know if the measured value is correct?Ī: The confidence of measured value agreement resides with the original manufacturing laboratory, the range of uncertainty of the technology being used, and the manufacturer''s practices and accreditations.įield proving activities can be used as a point of reference, but may be influenced by a number of factors.
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