This paper demonstrates that the quantum Hall effect can be used to monitor a laboratory unit of resistance. A 6453.2-? room temperature reference resistor was calibrated relative to two quantum Hall effect devices with a 0.017-ppm (1 ?) uncertainty for each 1 h measurement period. This accuracy was achieved by correcting for a measurement system offset error and for the temperature dependences of each quantum Hall device. Hamon series-parallel resistor networks were then used to calibrate the 6453.2-? resistor in terms of the five one ohm resistors which comprise the NBS ohm. The total l? accuracy for the transfer between the quantum Hall devices and the 1-? resistors was 0.047 ppm.