Determining and evaluatiting sources of uncertainty in the Tensile test

The measurement of a quantity has errors and uncertainties in the final size report, especially if this measurement is done with laboratory equipment. As a result, to obtain a more accurate value, attention is paid to the investigation and evaluation of the factors that create uncertainty in the final value. Therefore, in this research article, the factors and parameters that cause uncertainty in the final value of the tensile test, which is a widely used test for examining the mechanical properties of various materials such as steel in the construction of steel pipes for use in water, gas and oil transmission, are investigated. The device's uncertainty and the uncertainty resulting from the repeatability have been investigated and calculated. Finally, the ultimate stress of the tensile device in the laboratory of Qaem Pipe Rolling Company was investigated. The value of 72.62 kPa was calculated with an expanded uncertainty of 0.63 with a confidence factor of 95%. Also, according to the obtained information, the share of uncertainty of repeatability is more than other factors of uncertainty.