AFTE Store - Imada DS2-44 Digital Force Gauge: Trigger Pull Measurements and Associated Uncertainty of Measurements

The Harris County Institute of Forensic Sciences (HCIFS) Firearms Identification Laboratory (FIL) recently replaced their Chatillon brand mechanical spring gauges with the Imada DS2-44 digital force gauge for use in conducting trigger pull measurements of firearms submitted as evidence. The Imada DS2-44 digital force gauge was implemented to provide more reproducible and precise trigger pull measurements and valuable reviewable data. The gauge was validated and the uncertainty of measurement values were estimated for the main firearm types/actions, including single action rifle, single action shotgun, single action pistol, double action pistol, single action revolver, and double action revolver. This article will serve as a reference for laboratories interested in implementing the Imada DS2-44 digital force gauge, or similar gauges, and estimating trigger pull uncertainty of measurement.