Critical-current measurement systems must be extremely sensitive to the small differential voltage that is present across the test specimen as it changes from zero resistance state to the flux-flow resistance state. Consequently, these measurement systems are also sensitive to interfering voltages. Such voltages can be caused by ground loops and by common mode voltages. Specific methods for testing the sensitivity of critical-current measurement systems and for detecting the presence of interfering voltages are discussed. These include a simple procedure that simulates the zero resistance state and the use of an electronic circuit that simulates the flux-flow resistance state.
Citation: Advances in Cryogenic Engineering
Pub Type: Journals
integrity tests, measurement, systems