Transport behaviour of 1 ohm standard resistors.
Because not all standards laboratories are able to base the representation of the ohm directly on the quantum Hall effect, 1 ohm traveling standard resistors are still of importance. These traveling standards often show an insufficient transport behavior, i.e. the resistance value measured after a transport does not match the value which is expected from the formerly estimated drift rate. The reasons may be e.g. too large changes of temperature and/or pressure during transport as well as mechanical shocks and vibrations.
By this project long-term investigations are started to correlate the resistance behavior with the above mentioned parameters. For this purpose transports of resistors will be performed or simulated with the surrounding parameters being well defined or at least monitored.
PTB will start to investgate and simulate the transport behaviour of 1 ohm standard resistors which are kept in a thermostated enclosure during transport.