DETERMINATION OF THE METROLOGICAL CHARACTERISTICS OF PIPE PROVERS BASED ON THE CONCEPT OF UNCERTAINTY

In this paper noted that oil metering units are used to determine the amount of crude oil. The metering units of crude oil that implement the method of dynamic measurements, the amount of oil is determined by the readings of oil meters (turbine or mass flow meters). Such flow rate transducers (flow meters) are subject to verification during operation. The main reference means used for the calibration of flow transducers are pipe provers (TPP). Calibration of such reference units can be performed using reference meters (compact-prover), reference balance and using a reference pipe prover with a comparator. The methods of calibration pipe provers with the use of reference meters (standard volume measure), as well as a reference compact-prover with a comparator have been developed. These methods of calibration approbation during the calibration of reference pipe prover installations operated at the facilities of JSC "Ukrtransnafta". The method is considered, and also the structural scheme of calibration of TPP by means of the reference compact prover with the comparator is resulted. A mathematical model is developed taking into account the influential factors and algorithms for their evaluation, as well as the metrological characteristics of TPP are determined - the uncertainty budget is formed and the uncertainty of measuring the capacity of the pipe prover calibration unit is estimated. According to the results of calibration of TPP BHP -1100 company "VEGYEPSZER", Hungary, operated in the Branch "PDMN" JSC "Ukrtransnafta" (Kremenchuk) using the reference Compact Prover company Brooks Insntrument Division Emerson Electric Co., USA comparator - turbine flow meter Smith Meter series MVTM, USA, the relative extended uncertainty of TPP capacity measurement was 0,03%. The main contributions to the extended measurement uncertainty during TPP calibration were the standard uncertainties due to the influence of liquid volume expansion (liquid temperature measurement) in TPP and compact-prover, the standard uncertainty of the reference compact-prover and the experimental standard uncertainty  of pipe prover capacitance measurement result's mean value.