The HIC (Head Injury Criterion) calculation sounds simple — integrate the acceleration signal over time. In practice, getting a valid HIC number from a head impact test requires careful attention to signal conditioning, filtering, and sampling rate. Here's the technical detail. Sensor Setup The standard headform accelerometer setup per ECE 22.06, FMVSS 208, and related standards: Triaxial accelerometer at headform centre of gravity (CG) Accelerometer range: ±2000g (motorcycle) or ±500g (industrial) Sensitivity: 1–2 mV/g typical Natural frequency: >10 kHz (to avoid mechanical resonance in measurement band) Mount the accelerometer with minimal mass adapter — any added mass shifts the CG and invalidates the test.…