Measurement characteristics, calibrating conditions, calibrating equipment and calibration methods for abrasive accumulation Density meters are specified in the JJF (Mechanical) 045-2009 standard, which is the "Specification for calibrating abrasive accumulation Density meters". It is suitable for calibrating newly manufactured and neutralized abrasive accumulation Density meters to ensure the accuracy of measurement results. This standard is issued and implemented by the State Administration for Market Regulation, replacing the JJG (Mechanical) 3-1993 standard, which is of great significance for quality control in the abrasive industry.