Which Accelerated Stress Test Method is Right for Me?

Thermotron AST systems are able to perform various accelerated stress test methods such as Highly Accelerated Life Test (HALT), Highly Accelerated Stress Screen (HASS), Step Stress Testing among others. Each type of stress precipitates specific defects that might be missed by traditional testing methods and equipment.

HALT Testing

This method uses step-by-step cycling of environmental variables such as temperature, shock and vibration in order to force products to fail. It can also include the simultaneous cycling of multiple environmental variables (an example: aggressive temperature cycling and step-stress vibration testing) providing a closer approximation of real-world operating environments. Used as part of the product design process using prototypes, HALT quickly exposes product weaknesses allowing for improved product quality. HALT testing is performed multiple times after the weak components have been fixed, replaced or reinforced.

HASS Testing

This applies similar stresses to those used in HALT however, HASS is an on-going screening test, performed on regular production units. This type of testing aims to verify that actual production units continue to operate properly and quickly detects component or manufacturing irregularities.. Environmental variables such as fast temperature cycling, shock and multi-axis vibration as a means of screening 100% of production units may be used. HASS Testing indicates that the entire final product, including all components, will be reliable.

There are important factors to take into consideration when choosing appropriate equipment for HALT and/or HASS testing. Both of these testing methods require testing equipment capable of producing temperature and vibration simulatenously. Thermotron is able to provide powerful HALT/HASS performing Accelerated Stress Test (AST) Chambers in a variety of sizes and utilizing several different methods of cooling for the highest temperature change rates.

For more information about AST methods, read our AST Handbook.