Q: As a facilities engineer, what are my key considerations when planning for the purchase and installation of test chambers?
A: “Maybe we should always start everything from the inside and work to the outside, and not from the outside to the inside. What do you think?” ~Aidan Chambers, Postcards from No Man’s Land
When planning for the installation of test chambers, the wise facilities engineer takes heed of Aidan Chambers’s words, and plans from the inside out. For the test requirement driving the installation will also drive the engineering that the facilities person must accommodate.
But before working from the inside out, let’s take a 100,000-ft. view of test chambers to put us all on the same footing, starting from the inside in.
Test chamber 101
In the controlled environments world, a test chamber provides the ultimate delineation of specified conditions, allowing for precise testing. Also referred to as an environmental chamber, they can range in size from small units placed on benches, universal test machines, or other test apparatus to large rooms or standalone structures — it is, simply, a controlled environment enclosure that allows the testing of specific environmental parameters on a wide variety of materials — including electronic components, biologics, industrial products, or raw materials. The materials to be subjected to testing can range from raw materials to be utilized in the manufacture of a specific product, to final products that must withstand extreme conditions — humidity or temperature being just two. Because the range of applications for test chambers is so diverse, it’s wise to “start everything from the inside and work to the outside.”
A test chamber might be used to set the environmental conditions under which specimens need to be tested to determine how the specimen will perform under a range of environmental conditions in the “real world”; to condition or prepare the specimen for additional testing required for the manufacturing process or to simply determine the effects of certain conditions on the items being tested.
Test chambers are utilized by a wide variety of organizations: academics, R&D, manufacturing, government entities, and specialty nonprofits that are linked to technology and government agencies. While an electronics manufacturer might utilize a test chamber to determine how a component will react to humidity changes, an organization such as NASA might utilize a test chamber to ascertain how a piece of equipment will function over time while being exposed to extreme environmental conditions. Test chambers allow the acceleration of time – and the accurate analysis of the impact extreme environmental conditions will have on equipment or product over long periods of time. In this respect, test chambers function as a mini time machine, compressing the effects of real time to a manageable test period. Some of the common conditions tested include:
• Humidity: tolerance to wide ranging moisture and humidity conditions
• Temperature: the ability to test the impacts of both extreme hot and cold, as well as wildly fluctuating temperatures and sudden, extreme shifts in temperature
• Vibration: the ability to test the materials for performance and durability when subjected to ongoing, sudden, or surrounding vibration
• Weather conditions: the performance and reaction to a wide range of climatic conditions, including UV degradation
• Surrounding environmental impacts: examples include salt water exposure and its impact on corrosion, gravity or loss of, electromagnetic radiation, and altitude
• By-products and emissions: including off-gassing
Testing requirements can be quite straightforward, or very complex. These program requirements are the ultimate determinant of the level of sophistication required as you spec the unit. The test chamber can be set for very specific conditions, or programmed to run through a cycle of multiple variable conditions. Many test processes require the equipment either be Web-based or networked to other pieces of equipment.
One of the highest profile test chambers in recent years: Apple’s “Stargate Chamber,” which was featured in a Steve Jobs press event a few years back, with photos posted to their website and the Internet. According to the late Jobs, Apple invested more than $100 million at the time to engineer and construct 17 anechoic chambers to test their iPhones. The test chambers were used to test Bluetooth devices, cellular base stations, and replicating a host of environmental conditions that could impact the iPhone’s performance.
One hundred million dollars isn’t chump change. But you don’t need to have Apple’s budget to meet your requirements. Test chambers can be custom designed or purchased from an established supplier to meet relatively standard testing requirements. They available new or used, and as of this writing, there are even several test chambers for sale on eBay, ranging in price from a few hundred dollars to five figures.
Checklist for the facilities engineer
So, you need a test chamber for the latest imaginings of your R&D department. Following is a brief checklist as you head down that that happy trail:
• First, think about the items outlined above (yes, you do need to read the entire article). And remember, size matters. Building a new structure is a bit different than placing a prefabricated test chamber on a bench and hooking it up.
• Talk to your R&D, operations, and manufacturing people; they need to be responsible for specifying the performance parameters. You need to be responsible for ensuring it gets correctly hooked up and functional.
• Don’t forget the details. Do they need access to handle the samples being tested? The ability to observe visually? Do you need to light the interior? (If so, be sure to compensate for any excess heat from the light source.) Would surrounding or episodic vibration be an issue? What other surrounding conditions could impact the test chamber operation, efficiency, or accuracy — electro-magnetic interference?
• Required life expectancy?
• Do you need custom, or will used do?
• Networking requirements?
• What level of user control and programming will be required?
• Calibration requirements upon installation and on an ongoing basis?
• Workflow and process considerations?
Once you have these questions answered, your responsibility is to engineer the hook-up, oversee the installation and calibration, and make provisions for maintenance and repair.
Conclusion
The devil is in the details and the details are in the standards. Several organizations have tackled this challenge, and provide a wealth of information well beyond the scope of this column. Here are a few resources:
• American Society for Testing and Materials (ASTM): www.astm.org
• The Institute of Environmental Sciences and Technology (IEST): www.iest.org
• American Society of Heating, Refrigerating, and Air-Conditioning Engineers: www.ashrae.org
• NSF International: www.nsf.org
• International Organization for Standardization: www.iso.org
Richard Bilodeau’s 30-year career includes plant engineering positions in clean manufacturing. He has designed, operated, and supervised the construction of advanced technology facilities and engineered clean manufacturing facilities for lithium-ion batteries, medical devices, electronics, and pharmaceuticals. Contact: [email protected]
This article appeared in the September 2013 issue of Controlled Environments.
