An isolation test can be a number of different possible tests, and the context and industry in which the term is used will typically indicate the precise meaning of the term. In general, this type of test is used to isolate one part of a device, machine, or electrical system from the larger system in order to determine where a flaw or issue exists within the system. In engineering, for example, this type of test is usually performed in any type of system in which a current flows, regardless of whether the current is gaseous, liquid, or electrical. An isolation test will usually be used to disengage one part of the system from the source of the current, battery or pump, and then test that part for flaws.
In an electrical system an isolation test could be performed to find where a signal or current was being lost. If a computer is not turning on properly when it should be doing so, for example, then this type of testing is usually performed to find the problem. Another computer system that is working properly will usually be used to assist in performing an isolation test on various parts of the computer.
The isolation test may begin with the power supply being removed from the nonworking computer and then installed within the functioning computer. This isolates the power supply in order to test it within an otherwise functioning system. If the functioning computer no longer turns on, then the fault is likely to be with the power supply.
On the other hand, if the system works properly, then other individual aspects of the malfunctioning system will then be subsequently isolated and tested further. Each cable running from the power supply to other components, for example, can be tested individually. By removing other components, an isolation test can also be run on the motherboard, random access memory (RAM), central processing unit (CPU), and other parts of the computer.
A similar type of isolation test can be performed on other types of systems and devices as well. If reduced pressure is found within a system in which water or air is being pumped through a number of different tubes, each tube can be removed and isolated from the system, then tested to determine where the pressure is being lost. Of course, numerous problems could also exist, so an isolation test may often be performed on each part of a system, even after a single flaw or issue is located.