Because of the wide variety of different experiments and tests that are conducted in environmental test chambers, the variety of available chambers must be equally varied. Tests of pharmaceutical products’ resistance to humidity or high temperatures must be conducted in small chambers, tests of an engine’s performance in very low temperatures must be conduced in a medium-sized chamber and tests on the performance of very large equipment must be performed in chambers that are large enough to accommodate them. If a chamber is large enough to accommodate the free movement a person, either to prepare objects within the chamber or to be subject to tests within the chamber, that chamber is often referred to as a walk-in chamber.
There are many scenarios in which access to a walk-in chamber is necessary. One of the most common examples of a walk-in test chamber is the altitude or hypobaric chamber. These chambers are very commonly used to treat or prevent decompression sickness, which is caused by changes to the ambient external atmospheric pressure around a person. Such changes usually coincide with deep-sea diving or high-altitude flight in non-pressurized aircraft. These chambers must be large enough to accommodate a person’s entire body, as decompression sickness affects the whole body.
In addition to these kinds of chambers, very large test chambers that are used to test very large equipment often must be large enough to allow for supervising technicians to position equipment and prepare it for testing. Examples of such large walk-in chambers include the vacuum chambers used by NASA to test the resistance of equipment to the vacuum of space as well as large vibration/shock chambers used to test electronic devices. Because there are so many large-scale testing procedures, walk-in chambers are indispensable tools across industry.