Metrological evaluation of petroleum, his derivatives, natural gas and alcohol flow computers; Avaliacao metrologica de computadores de vazao de petroleo, seus derivados, gas natural e alcool

This work presents results of petroleum flow computers, his derivatives, natural gas and alcohol, used on fiscal measurements, appropriation and custodial transfer system. It is intended that the used proceed give subsides for the model approval and verify initially the flow computers, besides the periodic verification of installed flow computers. The test procedures are focused at the algorithm deviations, at the A/D (analog - digital) and D/D (digital-digital)conversion deviations, simulating static pressure transmitters, pressure differential, temperature, specific mass, BSW (Basic Sediment and Waste), and at the pulse counting deviations of the flow computer. The presented methodology is based on specific document for certification and initial verification of flow computers for the WELMEC (European Cooperation in Legal Metrology), and improved to attend the measurement requirements in Brazil. The test show various no conformities among the performance of tested flow computers compared with allowed values by the developed procedure.