The Extech SDL900 is a uniaxial AC/DC magnetic field meter that measures fields up to 30,000 Gauss (3000 mT) with SD card datalogging in Excel® format. It features ATC (Automatic Temperature Compensation), N/S pole detection, Min/Max, Zero for DC nulling, and 99-point manual memory. Ideal for MRI safety, power line assessments, motor diagnostics, and industrial EMF compliance.