Environmental Testing for Real World Conditions
Environmental testing is critical in ensuring your product performs under real world conditions
Environmental testing is the exposure of a specimen to environmental conditions that may affect its function or life. These conditions include temperature, humidity, precipitation, corrosive elements, ice, frost, and condensation. Exposing your product to these conditions helps to simulate the stress that they will encounter during usage and can help you to improve the quality of your product as well as anticipate warranty issues.
Some examples of issues that environmental testing can find early include warpage and delamination of automotive interior components, corrosion of products used in coastal regions, ice build up on compressors, display errors on screens, failure of fiber optic cables, and firearm jams – just to name a few.
There are several types of environmental testing available depending on the conditions your product will be exposed to and the types of issues it may experience due to these conditions. These tests include: climate cycling, temperature/humidity shock, accelerated life testing, climate aging, sun simulation, precipitation, corrosion (salt spray), icing and deicing, and condensing humidity. Often, depending on the application, several of these tests may be combined to truly evaluate how a part will perform in real-world conditions.
Temperature affects the ductility of material which may have adverse effects on the operation of your product at temperature. For instance, testing plastics at high temperatures is critical because heat can break the chemical bonds in polymers. When this happens, it often creates additional hydrocarbon groups (branched polymer) which increases the brittleness of the material.
Climate Cycling
Climate cycling evaluates a product’s function at varying temperatures after a given number of cycles. This process can cause expansion and contraction which may create stress at the areas where materials meet. Materials with low thermal conductivity, such as ceramics, will undergo expansion at different rates. The ramp rate or speed at which the temperature changes will affect the rate of expansion and compression, thus affecting the stress imposed on the part.
Humidity Testing
Humidity testing can reveal weaknesses in your product because whether the humidity is high or low, there are potential implications to the life of your part. In environments with high humidity, issues like corrosion, seal failure, electrical faults, and issues with adhesion efficacy tend to come up. Conversely, in low humidity settings there are issues with static electric discharge as well as drying and cracking of rubber and vinyl materials.
Thermal Shock Testing
Thermal shock testing involves rapidly changing the temperature and/or humidity that a part is exposed to. This leads to quicker expansion and contraction. In addition, this test will only heat and cool the surface, not the entire sample, creating stress cracks. These can cause a loss of strength (even if they are microcracks which cannot be seen by the naked eye). Learn more about thermal shock testing.
Accelerated Life Testing
Accelerated life testing (ALT) is used to evaluate a product’s operation by exposing it to elevated or reduced temperatures for a period of time. By using more extreme temperatures than the product might encounter in the real world, we are able to accelerate the aging process. This is often used to determine a product’s shelf life. Learn more about accelerated life testing.
Sun Simulation Testing
Sun simulation testing is a blanket term that includes several types of tests including natural exposure, Xenon arc, fluorescent-UV, and full spectrum solar simulation (metal halide). These types of tests are generally used to evaluate color fade, deterioration, heating effects, and warpage. Learn more about sun simulation testing.
Precipitation Testing
Precipitation testing is used to test for water ingress in conditions such as rain, snow, and hail. Temperature differentials between the part and ambient air causes a pressure gradient which helps to facilitate water ingress. Some issues often seen during precipitation testing include material swelling, increased weight, electrical failure, corrosion, fungal growth, and hail damage.
Icing and Deicing
Icing and deicing testing is commonly used on aerospace, marine, and rail components. Ice can impede the use of antennas, optical devices, and meteorological equipment on ships. These tests are used to evaluate the effectiveness of deicing methods as well as test for potential effects of the ice such as material cracking, added weight, inhibited movement, and damage to electrical instrumentation.
Salt Spray Testing
Salt spray or salt fog testing evaluates how a component will hold up to corrosive substances over time. Different solutions are used depending on the material and type of environment to which it will be exposed. Test solutions used include neutral salt spray (NSS), acetic acid salt spray (AASS), and copper accelerated acetic acid salt spray (CASS). Scribing may be used to evaluate rust creepage and coating delamination, depending on the specific application. Learn more about salt spray testing.
Condensing Humidity Testing
Condensing humidity testing evaluates a coating’s resistance to corrosion and other effects of high humidity environments. The process utilizes a temperature gradient to induce condensation to simulate dew formation. The condensation contains a large amount of dissolved oxygen which contributes to corrosion. This test can be combined with other corrosion tests such as salt spray.
Building on the success of their Greenville, SC testing facility, Cross Company is excited to expand their testing services in Mexico with a new facility located in Querétaro, Mexico. Both the Greenville and Querétaro laboratories offer extensive environmental testing services in large scale environmental test chambers which allow test engineers to recreate an array of conditions with temperature ranges from -70 degrees Celsius up to 180 degrees Celsius and relative humidity from 10% up to 95%. They also have the capability to conduct temperature and humidity shock testing, corrosion testing (NSS & CASS), precipitation testing, and condensing humidity testing.
