Altitude testing simulates environments with varying degrees of reduced air pressure, allowing you to measure the impact high or low altitudes may have on your products or packaging systems. Linkotest‘s altitude testing services provide insight into how your products and packaging systems will perform under these stressful conditions. In the commercial transportation industry, where products and materials are exposed to extreme altitudes through air and ground transportation, altitude testing is especially valuable.
If you want to learn about altitude testing, our guide is for you. It covers everything you need to know about altitude testing from definitions, importance, applications, and more. You’ll learn everything you need to know in this guide – let’s get started:
1. What is an altitude test
Altitude testing simulates products intended for operation or transportation at different altitudes. These tests typically simulate the low air pressure experienced when operating products at high altitudes, such as Mexico City, or when transporting products by air.
It is also common to perform operations and transport simulations at altitudes below sea level. However, tests that simulate high pressure underwater are often referred to as stress tests or intrusion protection (IP) tests. Also, tests performed at the extremely low pressures of outer space or near-Earth space are often referred to as vacuum tests rather than altitude tests.
In altitude testing, dwell times at each simulated altitude are typically between one hour and one day. It is also common to simulate ramp rates between altitudes that may occur during transport. Less commonly, very high ramp rate tests are performed to simulate rapid decompression, for example during an air travel emergency.
Manufacturers of any airborne equipment should consider the impact that high-altitude or low-pressure testing may have on your products. Low-pressure testing simulates problems that high altitudes can create, such as:
- Gas or liquid leaks from gasket-sealed housing
- Sealed container ruptures or explodes
- Changes in Physical and Chemical Properties of Low-Density Materials
- Unstable operation or failure of equipment due to arcing or corona
- Device overheating due to reduced heat transfer
- lubricant evaporation
- Unstable starting and combustion of the engine
- Hermetic seal failure
2. Why is altitude testing important?
Altitude testing (also known as low air pressure) simulates the reduced air pressure experienced at higher altitudes to assess the effect on your product or packaging system’s performance. When exposed to altitude pressures, sealed flexible packaging systems may fail. In fact, the altitudes experienced by trucking often exceed the levels experienced by commercial air transportation.
The stress of extreme altitudes can cause your products or packaging systems to fail. Damaged products can negatively impact your company’s profits and reputation. A product’s ability to safely traverse extreme altitudes can be determined by altitude testing.
Proper altitude testing will look at many factors that components experience at extreme altitudes. These include:
- Temperature: Average temperature drop of 3.5°F per 1,000 feet increase. Components designed for use in aircraft and aerospace equipment must not only withstand extreme cold, but also the rapid temperature changes experienced during takeoff and landing.
- Humidity: As temperature changes, humidity also changes. Sensitive components must also be able to withstand these conditions. Commercial and military equipment require tight tolerances, so humidity testing is required to ensure they will always provide the required performance.
- Pressure: In terms of pressure, MIL-STD-810, RTCA DO-160, and other standards define acceptable behavior for rapid decompression of interior and exposed aerospace equipment. Altitude testing helps you maintain compliance and provide a reliable product for any application.
Even if your application does not require compliance with MIL, RTCA, or other standards, taking the time to conduct proper testing can help your product stand out from the competition.
Many buyers view these standards as a guarantee of superior quality, delivering superior performance in any environmental or atmospheric condition. Your product can be effectively marketed by altitude testing to military standards in a crowded market.
3. Combining altitude with other tests
Altitude testing is sometimes done at the same time as other tests. In order to better simulate high-altitude cold environments, altitude testing can be conducted concurrently with temperature testing. Alternatively, high-temperature testing of air-cooled equipment is sometimes performed without any reduction in air pressure as a low-cost way of simulating the reduced cooling effect of low-density air at high altitudes.
4. Frequently tested products
- manufactures
- any airfreight product
- aviation parts
- electronic parts
- computer hardware
- auto parts
5. Common altitude tests
Standard Altitude Simulation
- Combining Altitude and Temperature Testing
- high altitude riding
- ASTM D4169
- MIL-STD-810
- MIL-STD-202
- and other military and commercial standards
In conjunction with temperature or vibration testing, altitude testing can be performed with operating or non-operating units.
6. Frequently asked questions
Some frequently asked questions are answered here.
1) Who should do the altitude test?
Every company should consider the effect of altitude on products and packaging. Altitude testing is used to evaluate a product’s operational performance as well as shipping and storage performance. In some products, ambient air pressure at different altitudes may have to be compensated for by pressure sensors. Both sites, Denver, Colorado, and Mexico City have elevations well above sea level, which can pose challenges to the proper operation of capital equipment.
From a packaging perspective, flexible materials are often sealed at sea level. As the altitude increases, the ambient air pressure decreases and the internal air pressure of the package increases, causing the package to expand. We might call it the “bag of chips” effect. If multiple packages are placed in a carton and handed over to the shipper, the packaging material may be damaged.
Foam cushioning materials can also be affected by low air pressure. Closed cell materials may break and offer less protection to the product. This may result in reduced cushioning performance and damage your products.
Some components and subsystems need to be able to function reliably under rapid decompression conditions. Of course, aerospace parts come to mind, but any part or subsystem can be affected by decompression. Safety equipment, seals, technical instruments, control devices, ejection systems, and optical equipment are some examples.
2) What factors will be considered in the altitude test?
Linkotest generates comprehensive and accurate results from our altitude testing service by considering several different factors. In addition to exposing a product or packaging system to varying degrees of reduced air pressure, our altitude testing simulates the temperature changes that cargo may face at extreme altitudes.
By considering multiple factors during altitude testing, we can more accurately replicate the environment a product or packaging system will be exposed to. The results produced by these altitude tests are very useful to manufacturers and designers to prevent product damage and optimize the shipping process.
3) What level should most altitude tests be done at?
Pressure differentials can create potentially harmful pressures on any enclosed air volume and can affect the product or packaging system. The decompression experienced by a product or packaging system during transport depends on the way it is transported.
Depending on the shipping method you intend to use, our altitude testing service simulates different altitudes. Typical altitude is 4,267m (14,000ft) and one hour is allowed. However, military standards and some European standards may require 12,192m (40,000ft)
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