The 515A Portable Calibrator is a precision voltage and resistance calibration source for on-site calibration of measuring instruments. AC or battery operation and small size, only 8 1/2"W x 3 1/2"H x 16"D and 13 lbs, Accuracy of ±0.003% or 30 µV. DCV: 0 to 999 µV (0.02 µV resolution), 0 to 1 and 0 to 10 V ranges (0.1 and 0 V steps), 100 V cardinal point ACV: 1, 10, 100 V cardinal points Resistance: 10 ohms to 10 Mohms