Watt within the then-existing system of practical units as "the power conveyed by a current of an Ampère through the difference of potential of a Volt." In October 1908, at the International Conference on Electric Units and Standards in London, so-called "international" definitions were established for practical electrical units. Siemens' definition was adopted as the "international" watt. (Also used: 1 ampere x 1 ohm.) The watt was defined as equal to 10 units of power in the "practical system" of units. The "international units" were dominant from 1909 until 1948. After the 9th General Conference on Weights and Measures in 1948,
Spreading resistance profiling least formula_6 thick. With the aid of calibration resistivity standards, formula_3 can be determined at each probing by the probe pair. A bias of 5mV is applied across the probe tips. The measured resistance can range from 1-ohm to one billion ohms. A "log R" amplifier or electrometer is used to measure the resistance. The modern SRP has two tungsten carbide probe tips placed about 20 um apart. Each tip is mounted on a kinematic bearing to minimize "scrubbing". The probes are lowered very gently onto a beveled piece of silicon or germanium. Although the loading of the probe tips