High?Precision Density Measurements of Energetic Materials for Quality Assessment

Even though helium pycnometry is considered a very precise method of density determination, its use to analyse factors influencing crystal quality (e. g. solvent inclusions, amorphous states, defects…) limited due the unknown inherent accuracy method. Previous studies have attempted identify best possible pycnometry. However, no robust has been proposed validate even precision obtained. This means that often occurring, seemingly random deviations never satisfactorily explained. In this study on measurements CL-20/HMX cocrystal and phase stabilised ammonium nitrate carried out with an AccuPyc 1340 TEC were quantified data analysis was developed judge certainty significance shows statistical tests such as t-test ANOVA cannot be utilised differentiate between samples or repeat measurements, points exhibit normal distribution. By utilising confidence intervals quantifying three major sources error (sampling error, change in barometric pressure during measurement, weight error), repeatability 0.015 % achieved enables differentiation good 0.05 %.