Highly Accelerated Stress Screening (HASS)

HASS consists of high and low temperature and 3 axis vibration testing performed either individually or in combination.

Highly accelerated stress screening is a technique for identifying process flaws in equipment during production. HASS subjects equipment to overstress conditions but at a level which does not affect design life.

For assistance in designing a HASS test program contact the laboratory. 


The search for means of reducing product design and development costs and for increasing operational reliability has led to various testing techniques for achieving these goals.

One of these techniques is the use of accelerated environmental testing which is performed by stressing equipment to various levels. These tests have been formalized into two procedures: highly accelerated life tests (HALT) and highly accelerated stress screening (HASS).

HALT is performed during the design phase of a project to determine the weaknesses in a product. The applied stresses are above the level normally seen in service. This procedure serves to highlight the weak areas and allows for changes well before the equipment is placed into production.

HASS is performed in the manufacturing phase of the project to verify that the design changes implemented in HALT were properly incorporated. It also shows that the quality control goals have not been compromised by manufacturing process flaws or problems with vendor supplied items.

HALT/HASS has amply demonstrated that it is capable of detecting latent defects that would have resulted in product failures during customer usage. As a result, product reliability is significantly enhanced. Furthermore, the costs of repairing failed products returned from the field are reduced.

Aero Nav Laboratories is now in possession of a HALT/HASS test chamber capable of performing these tests and, consequently, offers testing services to industry and the military