Mixed Mode: Sine on Random Vibration Testing, RoR, SoRoR

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 Mode Vibration Testing are: MIL-STD-810 Department of Defense Test Method Standard for Environmental Engineering Considerations and Laboratory Tests RTCA DO-160 Environmental Conditions and Test Procedures for Airborne Equipment

Altitude Testing: Low Pressure Vacuum Chamber

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 to a given duration at a specified altitude. Components sealed with internal fluid such as batteries or capacitors may fail or leak during altitude testing because an internal pressure results at rising altitudes as the external pressure is reduced.  It is also possible to power a product during…