# API RP 86:2005 pdf download

API RP 86:2005 pdf download.API Recommended Practice for Measurement of Multiphase Flow.

3.1.45 phase: A term used in the sense of one constituent in a mixture of several. In particular, the term refers to oil, gas, water, or any other constituent in a mixture of any number of these.

3.1.46 phase mass fraction: The mass flow rate of one of the phases of a multiphase flow, relative to the total multiphase mass flow rate.

3.1.47 phase volume traction: The volume flow rate of one of the phases of a multiphase flow, relative to the total multiphase volume flow rate.

3.1.48 pressure-volume-temperature (PVT) relationship: Application of Equations of State (EOS) to a composite fluid to calculate the change in properties in going from one set of conditions (P and T) to another.

3.1.49 random error: The result of a measurement minus its arithmetic mean, i.e. the error which deviates about the mean in an unpredictable, bipolar fashion. [Ref. 6, B.2.21]

3.1.50 reference meter: A flow meter used for the specific purpose of measuring the flow rate of one phase of the commingled stream, e.g. the liquid hydrocarbon flow rate. Sometimes reference meters are used to measure more that one phase. e.g. when total liquid flow and watercut arc measured to determine oil and water rates.

3.1.51 relative error: The error of measurement divided by a true value of the measurand. [Ref 6, B.2.20j

3.1.52 repeatability: The closeness of the agreement between the results of successive measurements of the same measurand carried out under the same conditions of measurement. [Ref. 6, B.2. 151

3.1.53 reproducibility of results of measurements: The closeness of the agreement between the results of measurements of the same measurand carried out under changed conditions of measurement, such as different location, time, reference standard, etc. [Ref. 6, B.2. 1 6j

3.1.54 result of a measurement: A value attributed to a measurand, obtained by measurement. [Ref. 6, B.2.l 1]

3.1.55 slip: Conditions that exists when the phases have different velocities at a cross-section of a conduit.

3.1.56 slip ratio: A means of quantitatively expressing slip as the phase velocity ratio between the phases.

3.1.57 slip velocity: The phase velocity difference between two phases.

3.1.58 specified imbalance limit: A limit on System Balance which is established for the purpose of satisfying contractual obligations and/or regulatory requirements.

3.1.59 standard conditions: A set of standard (or reference) conditions, in terms of pressure and temperature. at which fluid properties or volume flow rates are expressed.

3.1.60 standard deviation: The square root of the variance of a random variable.

3.1.61 standard uncertainty: An uncertainty of the result of a measurement expressed as a standard deviation. [Ref. 6,2.3.11

3.1.62 superficial phase velocity: The flow velocity of one phase of a multiphase flow, assuming that the phase occupies the whole conduit by itself. It may also be defined by the relationship (Phase volume flow rate / Pipe cross- sectional area).

3.1.63 system imbalance: The difference between the measured Master Quantity and the sum of the Individual Theoretical Quantities, sometimes referred to as the System Balance.

3.1.64 systematic error: The difference between the mean that would result from an infinite number of measurements of the same measurand, carried out under the same conditions, and the true value of the measurand. [Ref. 6, B.2.22]

3.1.65 true value: The underlying characteristic of the measurand which would be recorded if the measurement were perfect, i.e. there were no random or systematic measurement errors.

3.1.66 type A evaluation (of uncertainty): A method of evaluation of uncertainty by the statistical analysis of a series of observations. [Ref. 6, 2.3.2]

3.1.67 type B evaluation (of uncertainty): A method of evaluation of uncertainty by means other than the statistical analysis of a series of observations. [Ref. 6, 2.3.3]

3.1.68 uncertainty of allocation meter: The uncertainty of an Individual Theoretical Quantity relative to the flowing conditions experienced by the meter, which includes the uncertainty of the meter, any uncertainty in EOS application, as well as the uncertainties due to errors of ancillary devices such as pressure and temperature.