The DAT Tester is a battery-operated tester to verify the correct operation of DAT CONTROLER®PLUS series ESE Lightning Air Terminals. A high voltage is applied to the Air Terminal. Two test leads are used to connect the instrument and Air Terminal to be tested. The test unit displays a green LED to indicate air terminal is operational or two red LEDs to indicate if the air terminal is faulty. The test unit contains a rechargeable battery to allow portable use in the field.