Environmental testing has nothing to do with an evaluation of the earth’s environment. Not the environmental testing we’re writing about here anyway.
Also known as environmental simulation, environmental testing involves putting your electronic product through environmental extremes and then determining what hardware failures occur. This process is crucial for pinpointing design flaws for ensuring the reliability and ruggedness of your equipment.
Environmental testing is split into two types: climatic and dynamic.
Climatic testing is performed in climatic test chambers. They range in size from desktop to hangar-sized. The McKinley Climatic Laboratory at Eglin Air Force Base in Florida is 55,000 square feet, and accommodates a hulking Lockheed C5 Galaxy transport aircraft.
Dynamic testing is performed on shakers and similar devices. It includes testing for shock, vibration, and earthquake/seismic. See a video of MET’s MIL-S-901D Hammer Shock rig being constructed and deployed.
Highly Accelerated Life Testing (HALT) is a form of environmental testing that combines climatic and dynamic components. It integrates vibration into the chamber environment, where temperature and humidity extremes can also be applied simultaneously. HALT is a faster, more effective version of the old environmental stress screening (ESS).
Testing should be conducted during the development of your hardware, so that all failures can be determined before the design is finalized. It is much better to fail during environmental testing than to fail in service, possibly causing user harm and often leading to warranty or recall expense.
With HALT, failure is a good thing, although it might not feel like it. It serves as a catalyst for redesign that improves the durability and ruggedness of the device, allowing you to lower your product’s infant mortality rate and reduce claims under your product warranty.
MET Labs owns and operates dozens of environmental test chambers and an impressive shock/vibe/seismic capacity in multiple locations across North America, as well as 24-hour HALT Testing on both coasts. Contact us for a free fast-response quotation.
A draft of Revision G of MIL-STD-461 has not been released yet, but MET Labs has obtained information about proposed changes to the Military EMC test. As covered in this previous post, one of the primary changes is the incorporation of indirect lightning testing heavily leveraged off of Section 22 of RTCA/DO-160G. There is no lightning requirement in MIL-STD-461F, which was released in 2007.
There is one test that is very likely to be added to MIL-STD-461G: CS117
There are two additional tests that are being considered, but are much less likely to be included: RS106 & RS108
Information about the CS117 test:
- Derived from DO-160 Section 22 lightning induced transient susceptibility
- Includes Multiple Burst/Single Stroke same as DO-160
- Idea is not to change waveforms; services (Army, Navy, Air Force) would need to control the application
- Cable injection only – no pin injection testing
- Limited applicability (aircraft electronics) based upon specific program contact call out
Information about the RS106 test:
- Similar to RS105 (EMP free field test for equipment)
- Limited applicability – mainly for external stores (missiles, pods, ground equipment, etc.)
Information about the RS108 test:
- Similar to RTCA/DO-160 Section 23 Lightning Direct Effects
- Limited applicability (antennas or other external located items) based upon specific program contact call out
The rollout of MIL-STD-461G is currently scheduled for an initial draft in June 2013, a final draft in September 2013, and release in Fall 2014.
Want to know more about upcoming changes to MIL-STD-461? Consider attending one of these events:
In two days, MET is hosting a MIL-STD Testing Seminar in Santa Clara, California.
Next week, attend this Lightning Testing Webinar.
In August, Pittsburgh is hosting the EMC Symposium, where MET Labs is exhibiting in booth #1024.
Or contact us with questions or a quote request.
At this week’s 2011 International Symposium on Electromagnetic Compatibility in Long Beach, CA, Fred Heather of the US Navy in Patuxent River, Maryland, gave an overview on the proposed addition of electrostatic discharge (ESD) and lightning testing to MIL-STD-461. Heather is the Electromagnetic Environmental Effects (E3) Lead for the U.S. government’s F-35 Joint Strike Fighter Program.
Currently, MIL-STD-461 is at revision F, so the new standard version will be MIL-STD-461G.
The changes propose to add four additional tests:
These tests are primarily based on the requirements from RTCA/DO 160 sections 22 and 23.
These changes are largely being driven by the use of composite materials in airframe construction, including that used in the Boeing 787 Dreamliner and Airbus A380. Many composites don’t conduct lightning currents the way metal airframes do, leading to the possibility of higher voltages and currents affecting aircraft equipment.
The changes were proposed for revision F, except the Navy and Air Force reportedly couldn’t agree on pin injection testing, thus delaying its implementation.
Read more about the requirements of MIL-STD-461 and other military EMC tests.
For manufacturers of products that require military standard (MIL-STD) testing, but have more of a commercial than military application, it pays to explore whether the product can be exempted from restrictive provisions in the Arms Export Control Act and the International Traffic in Arms Regulations (ITAR).
If after reviewing the U.S. Munitions List and other relevant parts of the ITAR, in particular ITAR §120.3 and §120.4, you are unsure of the export jurisdiction of an item or service, you should request a Commodity Jurisdiction (CJ) determination from the U.S. Department of State.
Some resources to help with the application:
- All CJ requests must be submitted electronically using the 5-page DS-4076 CJ request form
- FAQs regarding the CJ process
- For general questions on CJ, contact the Response Team at (202) 663-1282 or DDTCResponseTeam@state.gov
Applicants are not required to be listed with the U.S. Department of State’s Directorate of Defense Trade Controls to submit a CJ request. Following a successful submission and electronic confirmation receipt, the applicant will receive a Commodity Jurisdiction case number via email within 48 hours.