The AEMC 6503 [2126.52] 1000V Hand Crank Megohmmeter / Insulation Tester. The AEMC 6503 Hand-Cranked Megohmmeter is a compact, self-contained, hand-cranked True Megohmmeter. This practical and dependable instrument is designed for a broad range of plant and field service applications, such as acceptance testing and preventive maintenance of wiring, cables, switchgear and motors. The easy hand-cranked operation provides a steady, DC voltage output across the entire range for consistently reliable readings. The Model 6503 has three test voltages for insulation resistance testing: 250V, 500V and 1000V. Test voltages are generated in full across the entire measurement range.