Customer Challenge A customer approached DES looking to find an accelerated test solution for an AC powered cooling fan used in one of their products. The product had been established in the marketplace and the company was now looking for ways to reduce cost by looking at different cooling fan suppliers. Most fans, however, have …
Continue reading Cooling Fan Reliability Testing Case Study →
DES recently performed package testing per ASTM standard, ASTM D7386-12.
Part 2 – Selecting a Lab and Performing Your Test If you have not done so yet, please check out Part 1 – Defining your project and Obtaining a Quote. You obtained quotes from a couple of vibration test labs. Your next task is to select a vibration test lab to perform your vibration test. …
Part 1 – Defining your project and Obtaining a Quote Vibration testing is a very specialized field, not very well understood by many. There are different types of vibration and there are an enormous number of vibration test specifications. Vibration testing equipment is very expensive to purchase forcing many companies to hire a vibration test …
Mixed Mode Vibration Testing is less common than Sinusoidal and Random Vibration Testing. However, it does have a special purpose for simulating specialized helicopter vibration or vibration from tracked vehicles such as tanks. The three mixed modes of vibration testing are: Sine-on-Random (SoR) Random-on-Random (RoR) Sine-on-Random-on-Random (SoRoR) Some common test standards that have specifications for Mixed …
Continue reading Mixed Mode: Sine on Random Vibration Testing, RoR, SoRoR →
A vibration resonance occurs when equipment or a product is exposed to an external forced vibration occurring at one or more of its natural frequencies. The resulting product response vibration is amplified and can be huge! Vibration resonances can cause severe damage to products and significantly shorten their life. Examples of vibration resonances can be …
Vibration of a mechanical system can be descried as an oscillatory motion about an equilibrium point. Certain vibrations of mechanical systems can be considered desirable, such as in musical instruments like a tuning fork or guitar. However, often times vibrations of mechanical systems are undesirable, producing wasted energy, unwanted noise and catastrophic failures. Therefore it …
Shock testing with long durations can be a challenging endeavor. DES recently had to perform a 35G peak, half sine shock with a 50 millisecond duration. The video below shows this shock test being performed. This sounds like an easy shock to carry out because a peak of 35G is low compared to many shocks. …
Continue reading Shock Testing: Long Duration Half Sine Shock →
Altitude (Low Pressure) Testing makes use of a vacuum chamber to simulate the effects of high altitude conditions. The pressure inside the altitude chamber can be reduced to correspond to the air pressure at a specific altitude. Products can be placed inside the altitude chamber and tested to determine if they will still function after exposure …
Continue reading Altitude Testing: Low Pressure Vacuum Chamber →
Thermal shock testing also called temperature shock testing or temperature cycling exposes products to alternating low and high air temperatures to accelerate failures caused by repeated temperature variations during normal use conditions. The transition between temperature extremes occurs very rapidly during thermal shock testing, greater than 15 °C per minute. Alternatively, temperature cycle testing uses …
Continue reading Thermal Shock Testing – Temperature Cycling →