ASME MFC-11–2006 pdf download – Measurement of Fluid Flow by Means of Coriolis Mass Flowmeters.
1 SCOPE ASME MFC-11 establishes common terminology and gives guidelines for the selection, installation, calibra- tion, and operation of Coriolis flowmeters for the deter- mination of mass flow, density, volume flow, and other parameters. Thecontentofthis Standardis applied to the flow measurement of liquids, gases, mixtures of gases, multiphase flows, and miscible and immiscible mixtures of liquids. 2 TERMINOLOGY, SYMBOLS, REFERENCES, AND BIBLIOGRAPHY Paragraph 2.1 lists definitions from ASME MFC-1M used in ASME MFC-11. Paragraph 2.2 lists definitions specific to this Standard. Paragraph 2.3 lists symbols (see Table 2.3) used in this Standard (see notes and superscripts). Paragraph 2.4 lists abbreviations (see Table 2.4) used in this Standard. Paragraph 2.5 lists references used in this Standard and a bibliography. 2.1 Definitions Copied From ASME MFC-1M accuracy: the degree of freedom from error, the degree of conformity of the indicated value to the true value of the measured quantity. calibration: (a) the process of comparing the indicated flow to a traceable reference standard (b) the process of adjusting the output of a device to bring it to a desired value, within a specified tolerance for a particular value of the input. cavitation: the implosion of vapor bubbles formed after flashing when the local pressure rises above the vapor pressure of the liquid. See also flashing. Coriolis flowmeter: a device consisting of a flow sensor and a transmitter which measures the mass flow by means of the Coriolis force generated by flowing fluid through oscillating tube(s); it may also provide measure- ments of density and temperature. cross-talk: if two or more Coriolis flowmeters are to be mounted close together, interference through mechani- cal coupling may occur. This is often referred to as cross- talk. The manufacturer should be consulted for methods of avoiding cross-talk.
flashing: the formation of vapor bubbles in a liquid when the local pressure falls to or below the vapor pressure of the liquid, often due to local lowering of pressure because of an increase in the liquid velocity. See also cavitation. flow calibration factor(s): calibration factor(s) associated with mass flow measurement. flow sensor: a mechanical assembly consisting of an oscil- lating tube(s), coil drive system, oscillating tube deflec- tion measurement-sensor(s), flanges/fittings, and housing. housing: environmental protection of the flow sensor. oscillating tube(s): tubes(s) through which the fluid to be measured flows. rangeability: Coriolis flowmeter rangeability is the ratio of the maximum to minimum flowrates or Reynolds number in the range over which the flowmeter meets a specified uncertainty and/or accuracy. repeatability ofmeasurement (qualitative): the closeness of agreement among a series of results obtained with the same method on identical test material, under the same conditions (same operator, same apparatus, same labo- ratory, and short intervals of time). repeatability ofmeasurement (quantitative): the value below which the absolute difference between any two single test results obtained under the same conditions, [see repeatabilityofmeasurement (qualitative)], may be expected to lie with a specified probability. In the absence of other indications, the probability is 95%. reproducibility (quantitative): the closeness of agreement between results obtained when the conditions of mea- surement differ; for example, with respect to different test apparatus, operators, facilities, time intervals, etc.
(c) Resultant differences for reproducibility may be larger than their repeatabilities because of the test conditions. secondary containment: housing designed to provide pro- tection to the environment if the oscillating tube(s) fail. transmitter: electronic system providing the drive and transforming the signals from the flow sensor to give output(s) of measured and inferred parameters; it also provides corrections derived from parameters such as temperature. uncertainty (ofmeasurement): the range within which the true value of the measured quantity can be expected to lie with a specified probability and confidence level. zero stability: maximum expected magnitude of the Cori- olis flowmeter output at zero flow after the zero adjust- ment procedure has been completed, expressed by the manufacturer as an absolute value in mass per unit time. 2.2 Definitions Specific for This Document base conditions: specified conditions to which the mea- sured mass of a fluid is converted to the volume of the fluid. error: the difference between a measured value and the “true” value of a measurand. NOTE: The “true” value cannot usually be determined. In prac- tice, a conventional recognized “standard” or “reference” value is typically used instead.