ANALISIS KETIDAKPASTIAN PENGUKURAN KEKUATAN TARIK DAN ELONGASI SPESIMEN SS304 BERBENTUK RING

Abstract

Uncertainty is a measure of the reliability of a measurement. One of the widely used uncertainty analysis approaches is the Guide to the expression of uncertainty in measurement (GUM). The steps for analyzing the uncertainty of a measurement have been described in detail by the GUM approach. Uncertainty analysis was carried out on tensile testing to determine the traceability of the data obtained. Tensile testing produces data in the form of tensile strength and elongation of the test material. Tensile strength is a quantity that involves the magnitude of the force and length. Elongation is the increase in length when pulling. The tensile strength of the ring-shaped sample will be affected by the cross-sectional area on both sides of the ring when a tensile stress is applied. So, to determine the uncertainty of the tensile test, an analysis of the contributors to the uncertainty is required. This paper provides an explanation of how to analyze the uncertainty of the measurement of tensile strength and elongation in a ring-shaped sample. In addition, the value of the uncertainty in the measurement of tensile strength and elongation of SS304 (in the form of a ring) will also be presented. The test results show that the average tensile strength of SS304 rings is 631.070 ± 26.976 Nmm^-2 with an expanded uncertainty of 50.451 Nmm^-2 at a 95% confidence level. In addition, at the same level of confidence, the average SS304 ring elongation result is 18.681% ± 2.425% with an expanded uncertainty of 2.867%. Data repetition or repeatability is the biggest contributor to the uncertainty in measuring the tensile strength and elongation of the SS304 ring.