There are different types of environmental testing labs meant for different purposes. There are two main forms of environmental testing – stimulation and simulation. The advantages, differences and applications between the two types of environmental testing can confuse people.
Simulation mimics the different conditions a product would see when it is in its normal use environment. Simulation is often known as a test to pass because the stresses applied to the product such as humidity, temperature and vibration don’t exceed the intended use. When the product passes the simulation test, it is ready for consumer or market use.
Stimulation uses stress to uncover the weaknesses and limits of a product, often stressing a product to a failure point and beyond. E.g., the temperature would increase gradually in an attempt to get the highest temperature at which that particular product will function and where damage will happen. When the product fails, it is determined whether the failure needs to be fixed before market introduction or whether the failure is acceptable. Stimulation is referred to as accelerated testing.
Burn in
This is a traditional form of environmental testing when large batches of items or products are tested at elevated temperatures to help in the precipitation of failures. Elevated temperatures are achieved using the heat from the products under the environmental test or from a heating element.
These tests are often done in environmental testing labs california with powered products and temperatures may be cycled, which causes a large degree of thermal cycling as these devices heat and cool. It is important to weigh the ease with which the burn-in test is implemented against the low screening effectiveness. This is why a lot of companies choose the temperature cycling method.
Temperature cycling
Demands continue to increase to reduce testing time and this leads to a growth in stimulations. Companies are transitioning to temperature cycling from burn-in testing. Temperature cycling involves a rapid change between predetermined extremes in temperature for multiple cycles. Whilst temperature cycling is considered more efficient and effective than burn-in, there are still some complications to overcome. For example, good airflow is important because it utilizes and maximizes heat transfer. It also ensures that the actual product temperature follows the air temperature in the chamber.
It also prevents the formation of cold/hot spots within the workspace of the chamber. The speed at which the chamber changes the air temperature, or the ramp rate is also an important consideration to make. Faster ramp rapes are effective stresses for a certain number of cycles. But it is important to understand that ramps that are too fast might cause undesired damage.
Environmental stress screening
Environmental stress screening is a type of environmental testing that some environmental testing labs use to identify weaknesses in the manufacturing processes and materials. In an environmental stress screening process, every product is often subjected to stimulus. The main objective of environmental stress screening is to get rid of products that are likely to fail early to reduce infantile mortality rates of the product.