ASME MFC-11M pdf download

ASME MFC-11M pdf download.MEASUREMENT 0F FLUID FLOW BY MEANS OF CORIOLS MASS FLOWMETERS.
ASME MFC-11M, ASME MFC-l I M, gives guidelines for the selection, instalLation, calibration, and operation of Coriolis meters for the determination of mass flow, density, volume flow, and other related parameters of flowing fluids. It also gives appropriate considerations regarding the fluids to be measured. The content of this Standard is primarily applied to the metering of liquids. This Standard also gives guidance, within specified limits, to the metering of other fluids, mixtures of solids or gas in liquids, and mixtures of liquids. Although Coriolis meters may be used for gas measurement, specific guidance for gas measurement is not within the scope of this Standard.
2 TERMS AND DEFiNITIONS
The terminology and symbols (Table I) used in this Standard are in accordance with ASME MFC-IM.
Terminology not defined in ASME MFC-IM but used in ASME MFC-I1M are also defined in this paragraph. Some items from ASMF. MFC-1M are also listed in this paragraph for easier reference.
accuracy qf ,ncasurcnu-nt: the degree of freedom from error; the degree of conformity of the indicated value to the true value of the measured quantity (see ASME MFC-l M).
calibration: for the purpose of this Standard, calibration strictly refers to the procedure by which the flowmeter is checked against a traceable reference and does not include adjustment to the calibration factors.
calibration factor(s): numerical factor(s), also called flow calibration factors, unique to each primary device and determined by flow calibration, which when programmed into the transmitter, enables the meter to perform to its stated specification (see the note in para. Al of Appendix A for a definition of calibration).
dnsity calibration factor(s,I: calibration factor(s) associated with density measurement.
flow calibration factor(s): calibration factor(s) associated with mass flow measurement.
cavitation: the violent collapse of vapor bubbles formed after flashing when the line pressure rises above the vapor pressure of the liquid (see ASME MFC-IM).
5.4 Zero Adjustment
After the meter installation is complete, a zero adjustment might be needed to overcome the effects described in para. 5.3. It is recommended that zero be checked and adjusted if the offset is unacceptable. Zero adjustments should be made according to the manufacturer’s instruction. In general, to check or adjust the zero flow, the meter should be full and all flow stopped. Zero adjustment should he made under process conditions of temperature, pressure, and density. It is essential that the fluid remain stable and that there are no bubbles or heavy sediment and no fluid movement.
5.3 CalibratIon of Mass Flow
Most CorioLis meters are calibrated against a traceable standard by the manufacturer, and calibration certificates for the meter might be provided. The calibration factors determined by this procedure should be noted on the sensor data plate.
The calibration is the process of comparing the indicated flow to a traceable standard. The uncertainty of the calibration can be no less than the uncertainty of the reference standard and any errors that are introduced during the calibration.
As the Coriolis meter is a mass flow device, it is preferable to perform the calibration against a mass or gravimetric reference. Calibration against a volume standard combined with density determination can be used in situations where mass or gravimetric methods are not available.
A Coriolis master meter can be used to calibrate other Coriolis meters, The calibration of the Coriolis master meter must also be traceable to recognized standards. The same uncertainty ratios are needed for a master meter calibration as for a gravimetric calibration. Care must be taken so that cross-talk does not affect the calibration. (See para. A2.4 in Appendix A for additional information.)
Detailed calibration advice, calibration intervals, suggested procedures, calibration levels, and an example of a calibration curve are given in Appendix A.
6 DENSITY MEASUREMENT UNDER METERING CONDITiONS
6.1 General
Some Coriolis meters can provide density measurement under metering conditions. This paragraph includes recommendations for density calibration. Density-based inferred measurements such as standard density and concentration are covered in para. 8.
6.2 PrincIple of Operation.