Extech Launches New Pocket-Sized Autoranging Light Meter Extech’s pocket-sized autoranging Light Meter offers wide light intensity ranges measuring up to 40,000Fc (400,000Lux) with high resolution to 0.01Fc (0.1Lux). Ideal for indoor lighting tests and for checking security and safety illumination in parking garages, night time ATM areas, stairwells, landings, and hallways.