CALCULATION OF MEASUREMENT UNCERTAINTY IN ASTM D-4737 CALCULATED CETANE INDEX TESTING AND ASTM D-445 KINEMATIC VISCOSITY IN CEPU PPSDM OIL LABORATORY

Uncertainty is a parameter that defines the range of values ​​in which it is estimated that the true measured value lies. The concept of uncertainty is very important for measurement results, because uncertainty expresses the quality of measurement or test results. Measurements and tests have not been declared complete without an uncertainty value. The smaller the value of uncertainty, the more accurate and precise the results of the research or test carried out will be. The purpose of this Field Work Practice  is to determine the uncertainty value of the Calculated Cetane Index (CCI) ASTM D-4737 and Kinematic Viscosity ASTM D-445 tests in the Cepu Migas PPSDM laboratory. In testing the measurement uncertainty with CCI ASTM D-4737 and Kinematic Viscosity ASTM D-445 using diesel as a sample, the test was carried out for 7 days with 2 repetitions of the test every day. ± 6,980, and the results of the calculation of uncertainty by testing the Kinematic Viscosity ASTM D-445 is ± 0.40. Based on these results, the data obtained can be accepted because the results obtained are smaller than the reproducibility value.