To ensure this degree of reliability in such extreme surroundings a large number of tests is performed on individual components taken from normal production lots. The rigorous testing includes ageing tests, detailed visual inspections and vibration tests.
Most of the resistors deployed in space are manufactured using ISA-PLAN technology. This process ensures a high continuous load capacity (3 watts) as well as a high pulse power rating. Also, the temperature increase is low, leading to a correspondingly low resistance drift. In comparison with copper the electro magnetic force (EMF) of the resistor material Manganin is extremely small (less than 1 µV/K) and it has a very good long-term stability rating (better than 0.5 % at full load).
Isabellenhütte’s resistors have already been used in satellites for 12 years. Its adoption into the space technology authorities’ official supplier list for certified components, the European preferred parts list (EPPL), has been announced and is expected shortly.