Discussion on Uncertainty Evaluation of Determination of Epoxy Powder Density for Pipeline Anticorrosion by Density Cup Method

This paper mainly discusses and analyzes the influencing factors of the measurement results of epoxy powder density for pipeline anticorrosion by GB4472 -1984 pycnometer method, and evaluates the uncertainty of measuring the density of epoxy powder by pycnometer method according to JJF 1059 -1999. The experimental results show that when the epoxy powder density is 1.595 g/cm3, the expanded uncertainty of the measurement results is 0.026 g/cm3, k=2. As an excellent anti-corrosion coating, epoxy powder is widely used in the external anti-corrosion of natural gas and oil pipelines. A large number of epoxy anti-corrosion coatings have been used in large-scale projects such as the National West-to-East Gas Transmission and Sichuan-to-East Gas Transmission. The performance and quality of various raw materials used in the project need to be strictly tested and checked. Density, as one of the basic quality parameters of epoxy powder, needs to meet the technical indicators specified by the project. SY/T0315-2005 "Technical Specifications for Single-Layer Fusion-bonded Epoxy Powder External Coatings for Steel Pipelines" specifies that the method for measuring epoxy powder density is GB4472 "General Rules for Determination of Density and Relative Density of Chemical Products" [1]. As a powder sample, generally only the specific gravity method in GB4472 can be used for density determination. In order to ensure the reliability of the measurement results, the author analyzed and evaluated the influencing factors and measurement uncertainty .