In the demanding realms of aerospace and defense, ensuring that products can withstand the rigors of high-altitude environments is paramount. MIL-STD 810 is a Department of Defense Test Standard for environmental engineering considerations and laboratory tests.  Method 500 in MIL-STD-810 defines procedures for low-pressure (altitude) testing.  The latest revision of this method is 500.6 from MIL-STD-810H.

Altitude Testing Services at Delserro Engineering Solutions

At Delserro Engineering Solutions, our altitude testing services are designed to meet the rigorous demands of the aerospace and defense industries. By employing the comprehensive procedures outlined in MIL-STD-810H Method 500.6, we ensure that every product undergoes thorough low pressure testing under simulated high-altitude conditions. The altitude test chambers at Delserro Engineering Solutions (DES) can meet the requirements of MIL-STD-810H (and previous revisions) accurately ensuring that products are not just compliant but are primed for operational excellence.

MIL-STD-810 altitude testing services are tailored to products that:

1. Operate or are stored at significant elevations.
2. Experience pressurized or unpressurized conditions in aircraft.
3. Could undergo rapid or explosive decompression.
4. Are externally mounted on aircraft and exposed to extreme conditions.

Method 500 is not intended for items that are installed or operated in space vehicles, aircraft, or missiles that fly at altitudes above 21,300 m (70,000 ft). 

The following are typical failures that could occur from products used in a high altitude (low pressure) environment:

1. Leakage of gases or fluids from gasket-sealed enclosures
2. Deformation, rupture, or explosion of sealed containers
3. Change in physical and chemical properties of low-density materials
4. Overheating of materiel due to reduced heat transfer
5. Evaporation of lubricants
6. Erratic starting and operation of engines
7. Failure of hermetic seals
8. Erratic operation or malfunction of materiel resulting from arcing or corona

MIL-STD-810 Method 500.6 Insights for Low Pressure Testing

MIL-STD-810 Method 500.6 has four procedures:

1. Procedure I – Storage/Air Transport. Procedure I is for testing material that is transported or stored at high ground elevations or transported by air in its shipping/storage configuration.
2. Procedure II – Operation/Air Carriage. Procedure II is used to test the performance of products operated at high altitudes.  It may be preceded by Procedure I.
3. Procedure III – Rapid Decompression.  Procedure III is for determining if a rapid decrease in cabin pressure will cause a failure or malfunction that would endanger nearby personnel the ground vehicle or the aircraft in which it is being transported.
4. Procedure IV – Explosive Decompression. Procedure IV is similar to Procedure III except that it involves an instantaneous decrease in pressure.

How is MIL-STD-810 Low Pressure Testing performed?  First, it is necessary to determine the test parameters such as test altitude (pressure) and temperature, rate of change of pressure (and temperature if appropriate), duration of exposure, and test item configuration based upon the Life Cycle Environmental Profile.  Once the parameters are defined, low pressure testing is performed by placing the specimen in a specialized chamber that simulates altitude by controlling pressure and temperature.  Upon completion of the altitude test, DES will promptly deliver a detailed test report that includes the customer’s name and address, the test dates, a summary of the test procedure, equipment & measuring system calibration information, plots of altitude and temperature, test observations & results, color pictures of the altitude test setup and color pictures of any failures. 

Why Choose DES for MIL-STD-810 Low Pressure (Altitude) Testing

• A2LA Accreditation: Our laboratory’s accreditation is a testament to our commitment to quality and excellence in environmental testing.  DES is A2LA accredited to MIL-STD-810 Low Pressure (Altitude) Testing.
• Trusted by Industry Leaders: Our state-of-the-art testing facilities, experienced engineering team, and track record of success has made us the number one choice of top defense contractors.
• Advanced Testing Capabilities: With equipment capable of simulating altitudes from below sea level to as high as 1,000,000 feet and temperatures ranging from -75°C to +150°C, we can accommodate a wide variety of testing requirements.

Contact us today to discuss how our altitude testing services can contribute to the success and reliability of your next project.

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DES recently performed package testing per ASTM standard, ASTM D7386-12.  The test included shipping vibration testing which was conducted on DES’s Unholtz Dickie ED Shaker System.  ASTM D7386-12 requires packages to withstand random vibration levels of approximately ½ Grms over the frequency range 1 – 200 Hz.  This test is meant to simulate environments these packages could see in the field.  It is extremely important for manufacturers to test the effectiveness of their package designs prior to product shipment.  Shipping environments can put a lot of stress on products.

Improper package design can cause products to fail when the customer receives the product.  Environments such as high altitude, temperature, humidity, vibration and shock are common for most packages.  High return rates due to damage during shipment can cripple a company’s bottom line.  Prevent this from happening and send DES your packages to test!

Other package testing standards DES is capable of include (but not limited to):

• ISTA 1 Series
• ISTA 2 Series
• ISTA 3 Series
• ASTM D3580 Vibration (Vertical Linear Motion) Test of Products
• ASTM D4169 Performance Testing of Shipping Containers and Systems
• ASTM D4728 Random Vibration Testing of Shipping Containers
• ASTM D7386 Performance Testing of Packages for Single Parcel Delivery Systems
• ASTM D999 Vibration Testing of Shipping Containers

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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 the test to verify that it remains operational during the altitude test. The lower pressure at higher altitudes can reduce the cooling of components which can lead to possible failures. For this type of testing, it is necessary to have power and signal wires that can be fed into the altitude chamber without causing vacuum leaks. DES can provide a generic feed through that can be used for most testing. A custom feed through can also be fabricated if the component to be tested has specialized power or signal cables. It will be necessary to seal these cables to maintain the low pressure.

Altitude testing is normally conducted at room temperature. It is also possible to perform altitude testing at hot and cold temperatures. This will increase the test time as additional time will be required to heat up or cool down the altitude chamber.

Delserro Engineering Solutions, Inc. (DES) has many years of experience performing altitude testing and can assist customers in setting up a test using the proper test conditions. So if you do not know what test conditions that you should use, what specification to choose then we will help you because we are altitude testing experts!

Examples of common altitude testing specifications:

• IEC 60068-2-13, Low Air Pressure
• MIL-STD-202, Method 105, Barometric Pressure (Reduced)
• MIL-STD-810, Method 500, Low Pressure (Altitude)
• MIL-STD-883, Method 1001, Barometric Pressure, Reduced (Altitude Operation)
• RTCA/DO-160, Section 4, Temperature and Altitude

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