A test system is a complex network of several measuring and simulation devices that are used to test the behaviour of a technical apparatus or process under certain boundary conditions. In many cases, a test system is also set up to determine the existence of certain properties. While the result of an experiment is not known in advance, test systems serve to verify an expectation that should be empirically confirmed in the course of the test procedure.
A further difference is that experiments must be measured by the repeatability of their results, while statements that a test system can make with regard to an object or a technical device are always limited to this application. For test systems used in metrology, it is particularly important that all measuring devices have been calibrated beforehand to ensure the comparability of the devices involved in the test system.