Chauvin Arnoux CA 742 [P01191742D] Volt Tester. Chauvin Arnoux CA742 is a voltage detector with indicator lights. It is an instrument of choice for electricians checking that no voltage is present before working on an electrical installation connected to the network. It complies with IEC 61243-3 Edition 2 and can be used to work on any indoor or outdoor 600 V CAT IV installation. To fulfil the requirements of the standards and legislation in different countries, RS offers different versions - without IP2X accessories ( 914-0021 ) and with IP2X accessories ( 914-0025 ). The CA742 is equipped with a redundant safety system in the event of power supply faults. An 'ELV LED' flashes whenever the voltage exceeds 50 V AC / 120 V DC. The full Autotest of the CA742 checks the electrical circuits, the power supply, the display and the condition of the measurement leads.