Petroleum och motsvarande tekniker

This document specifies a test method for the quantitative determination of ignition and combustion delays of middle distillate fuels intended for use in compression ignition engines. The method utilizes a constant volume combustion chamber with direct fuel injection into heated, compressed synthetic air. A dynamic pressure wave is produced from the combustion of the product under test. An equation is given to calculate the derived cetane number (DCN) from the ignition and combustion delays determined from the dynamic pressure curve. This document is applicable to middle distillate fuels, fatty acid methyl esters (FAME) and blends of diesel fuels and FAME. The method is also applicable to middle distillate fuels of non-petroleum origin, oil-sands based fuels, blends of fuel containing biodiesel material, diesel fuel oils containing cetane number improver additives and low-sulphur diesel fuel oils. However, users applying this document especially to unconventional distillate fuels are warned that the relationship between derived cetane number and combustion behaviour in real engines is not yet fully understood. This document covers the ignition delay range from 2,6 ms to 3,9 ms and combustion delay from 3,78 ms to 6,56 ms (62,78 DCN to 39,44 DCN). NOTE The combustion analyser can measure shorter or longer ignition and combustion delays, but precision is not known. WARNING - The use of this document can involve hazardous materials, operations and equipment. This document does not purport to address all of the safety problems associated with its use. It is the responsibility of users of this document to take appropriate measures to ensure the safety and health of personnel prior to application of the document, and fulfil statutory and regulatory requirements for this purpose.

This document specifies a method for the determination of arsenic content in crude oil using atomic fluorescence spectrometry. Microwave digestion is used for pre-treatment of the oil sample into an inorganic solution.

ISO 4259-2:2017 specifies the methodology for the application of precision estimates of a test method derived from ISO 4259‑1. In particular, it defines the procedures for setting the property specification limits based upon test method precision where the property is determined using a specific test method, and in determining the specification conformance status when there are conflicting results between supplier and receiver. Other applications of this test method precision are briefly described in principle without the associated procedures. The procedures in ISO 4259-2:2017 have been designed specifically for petroleum and petroleum-related products, which are normally homogeneous. However, the procedures described in ISO 4259-2:2017 can also be applied to other types of homogeneous products. Careful investigations are necessary before applying ISO 4259-2:2017 to products for which the assumption of homogeneity can be questioned.

ISO 4259-1:2017 specifies the methodology for the design of an Interlaboratory Study (ILS) and calculation of precision estimates of a test method specified by the study. In particular, it defines the relevant statistical terms (Clause 3), the procedures to be adopted in the planning of ILS to determine the precision of a test method (Clause 4), and the method of calculating the precision from the results of such a study (Clauses 5 and 6). The procedures in ISO 4259-1:2017 have been designed specifically for petroleum and petroleum related products, which are normally considered as homogeneous. However, the procedures described in ISO 4259-1:2017 can also be applied to other types of homogeneous products. Careful investigations are necessary before applying ISO 4259-1:2017 to products for which the assumption of homogeneity can be questioned.