Experimental Verifcation of the Five-Terminal Ten-Kilohm Resistor as a Device for Dissemination of the Ohm

An experimental evaluation of five-terminal 10-kilohm hermetically sealed standard resistors as interlaboratory (transport) standards indicates that the typical drift is +0.4 ppm per year; the effects of mechanical shock to 100 G and of vibration up to 10 G at 80 Hz, less than 0.1 ppm; the effect of hot shock to 65° C, less than 0.1 ppm after five days recovery; the effect of cold shock to -20° C, less than 0.1 ppm; the effect of temperature, applying corrections, 0.06 ppm over the range 18 to 280°C, and ignoring corrections, 0.92 ppm over the range 20 to 260°C. Greater precision of comparison can be achieved at the 10-kilohm than at the 1-ohm level. Incidental to the test, agreement among the values of the ohm as derived from the computable capacitor at NSL, Australia, and from the national standards at NBS (USA) and NRC (Canada) were found to be within 0.3 ppm of the expected values from data published by the International Bureau of Weights and Measures.