The Model 731A DC Transfer Standard is a versatile instrument, providing a variety of precision voltages with standard cell accuracy. It will furnish basic outputs of 1.000 volts, (1.018 + AE) volts, (1.019 + AE) volts, 10.000 volts, and AE (0 to 999 microvolts). The AE control is a precision 10-turn linear potentiometer which has a 3-digit direct reading dial. The control is equipped with a locking lever which prevents accidental changing of the AE setting. Resolution of the control is 1 microvolt, thus allowing 1 microvolt steps (to 999 microvolts) to be added to the 1.018 and 1.019 volt outputs. The AE output may be selected independently as well.