UEi Test Instruments ECT690 Electrical Tester AC Volts 12 to 690 CD Volts 6 to 220 UEi Test Instruments has over 45 years experience designing and manufacturing a broad range of industry-leading Test and Measurement Tools UEi Test Instruments are sold throughout North America. Professionals recognize the UEi brand for quality and innovative features UEi's NIST-certification laboratory is compliant with ISO17025. UEi backs its products with dedicated technical support, service and repair teams