A test chamber is a specially manufactured controlled environment that companies use to check the endurance or stability of equipment, products, and substances. Environmental test chambers simulate the climactic conditions that products are most likely to encounter during use. These conditions might include extreme changes in temperature or humidity, altitude, or geographical location. Testers might also perform dynamic testing, exposing products to physical forces that including inertia or vibration in an attempt to reveal faults before products are use in flight or at high rates of speed. Companies might use test chambers for completed or partially completed products.
Manufacturers design and construct test chambers in a number of sizes ranging from 2 cubic feet (0.05 cubic meters) of space to entire room-sized chambers. Most contain stainless steel interiors, and some are equipped with internal lighting and viewing windows. External control panels enable testers to program desired environmental tests for specific lengths of time. Depending on specific need, available testing units perform one or more tests. Test chamber manufacturers offer units for retail or rent to industrial and military sectors.
Temperature test chambers often contain infrared lighting to simulate heated environments and refrigeration units for simulating cold. Companies perform thermal stress testing by exposing equipment or objects to rapidly changing temperatures. Testing can occur while equipment being tested is operational or non-operational. Depending on the particular test chamber, temperatures may descend to -100 degrees Fahrenheit (-73 degrees Celsius) and may rise to 850 degrees Fahrenheit (538 degrees Celsius).
Companies often expose equipment or products to extremes beyond normal conditions, to determine ultimate stress tolerances. Humidity test chambers create environments that are hot and that contain moisture-filled air. This type of test chamber often performs condensing and non-condensing tests. By adjusting the temperature and humidity levels of the chamber, researchers may induce moisture condensation. Controlling the environment also allows testers to expose equipment or products to a "breathing" process, which pulls moisture from the air into the test object, thereby checking for moisture resistance or the level of function after moisture has been absorbed.
Companies also use test chambers made of clear plastic that simulate the atmosphere of coastal salt-laden, moist air. Equipment or objects designed for use in tropical locations might undergo fungal testing that uses fungal or mold spore cultures combined with heat and humidity. Other test chambers might expose test objects to thermal vacuum environments, similar to the atmosphere found in outer space. Centrifuge devices, shaker tables, and other mechanical devices placed in a test chamber replicate a variety of physical stressors.