Megohmmeters/Insulation - AMEC
Read - Understanding Insulation Resistance Testing
AEMC is an industry leader in current measurement probes, power quality analyzers, ground resistance testers and insulation resistance testers. It was Founded in 1893.

AEMC Instruments - 200 Foxborough Blvd., Foxborough, MA 02035 USA
Seen above is the Megohmmeter from AEMC. 6505 is a portable battery/mains powered instrument in a rugged field case.
This Features include automatic calculation and presentation of the Dielectric Absorption Ratio (DAR) and Polarization Index (PI). The Model 6505 displays the test voltage, insulation resistance and the leakage current during the test.