RESISTANCE MEASUREMENTS FROM 10 MΩ TO 1 TΩ AT NIST

摘要

Described are the measurement systems and methods used for calibrating standard resistors from 10 MΩ to 1 TΩ at the National Institute of Standards and Technology (NIST). Presently four systems are used for the calibration of standard resistors at and above 10 MΩ. An automated guarded multimegohm bridge has recently been developed to augment a manual guarded Wheatstone bridge and a semiautomated teraohmmeter system. An automated resistance ratio bridge is used during the scaling process. Scaling from one decade to the next is done by using guarded Hamon boxes and the high resistance bridges.