The Datron 4200A Autocal AC Standard is the most accurate programmable AC source available. It is the ultimate prime AC source for any standards or calibration laboratory, achieving levels of stability and accuracy in hostile environments previously only available in temperature controlled laboratories. It features 90-day performance to plus/minus 40 ppm on a 6 1/2-digit scale, with output ranges from 1 mV to 1100 V. The frequency range available is from 10 Hz to 1 MHz, and a Spot calibration feature can be used to eliminate flatness component of the accuracy specification, providing even higher accuracy at these user-defined spot frequencies. Being fully programmable via the IEEE-488 interface makes the Datron 4200A one of the most versatile AC standards available and perfectly suited for ATE systems to automate calibration of DMMs.