HALTHASS & Combined "Shake 'n' Bake"

HALT (Highly Accelerated Life Testing) – a complete subject in itself; in essence a combined 6 degree of freedom vibration process with rapid temperature cycling as well. Fundamentally this process can expose defects in days that would otherwise take weeks of traditional testing or years of field use to show up.

HASS (Highly Accelerated Stress Screening) is designed to expose latent defects incurred during manufacture that would otherwise surface as field failures. 

Graph of Field Stress and Product Strength distributions

HASS can be a useful tool for cutting overall manufacturing time. If used intelligently HASS can reduce or remove extended time processes such as “conditioning” or “burn in”. 
Typical problems HASS identifies:

  • Certainty for whether substituted components compromise existing design/product integrity
  • Poor manufacturing implementation of a sound design, e.g. dimensional tolerances, hidden mechanical handling damage, component stress from poor placement alignment etc
  • Poor or incorrectly applied manufacturing techniques, e.g. Overheated PCB tracks lifting, dry joints, components mounted with extended or short wire tails, wire/harness tension or point load fret problems. 

Development of a properly structured HASS profile requires previous data from:

  • Previous HALT results
  • Product information data
  • Validation of procedure
  • Products powered and monitored whilst under test

Combined Testing – a more familiar alternative to HALT testing with traditional Vibration, Temperature & Humidity cycling are combined to suit specific test regimes, standards compliance, or simulation of extreme service conditions. It is possible to compress normal operational environment conditions from months/years into hours, days & weeks.

We have a number of shaker systems and a combined shaker/environmental chamber to cover a very diverse range of testing needs. For more, please see our Test Services or Sales & Hire pages or simply contact us.

Further reading? Qualmark have some excellent resources available on their website.