Designed with Standards and Calibration laboratories in mind, the 4920 provides extremely high performance in AC Voltage measurement, combined with ease of use. Standard and Optional Measurement Facilities Basic Configuration The 4920 is a high-quality Alternating Voltage Measurement Standard. Its basic configuration offers the following measurement capabilities: • High Accuracy mode - RMS AC Voltage measurement in eight ranges from 90mV to 1100V; 1Hz to 1MHz; 1-year specifications to ±30ppm. Input Impedance > 200Ω/V. Display resolution to 100nV maximum. • Transfer mode - Ranges and resolution as ACV. AC/DC or AC/AC transfers performed faster and more easily than with normal thermal transfer devices.. • Millivolt Ranges (Option 10) - Measurements from 0.9mV to 110mV in four ranges. • Menu Control - flexible and easy to use. • Calibration - Autocal external calibration. • Remote Control - Fully IEEE-488.2 programmable.