The Fluke 1503 digital megohmmeter is an insulation tester with two test voltages—500 and 1,000V—for measuring insulation resistance to 2,000MΩ to indicate the condition of windings or cables in motors, switchgears, electrical installations, and other insulated equipment, and it also measures low-resistance to 20kΩ and AC and DC voltage to 600V, disabling insulation testing when a voltage greater than 30V is detected. When a resistance measurement is complete and the test button is released, residual voltage is automatically discharged from the circuit under test. The lock button enables extended measurement sessions. The meter has an LCD with a backlight for visibility in low light that automatically turns off after two minutes. It is rated for category (CAT) IV installations to 600V, which covers equipment at the origin of the installation, such as electricity meters and primary over-current protection equipment. The unit has a low-battery indicator that signals when the batteries need to be replaced, and automatically turns off after 10 minutes of non-use. It comes with four AA batteries, a remote probe for testing in tight spaces, a set of test leads, a set of test probes, a set of alligator clips, and instructions. For the extended lead kit model, B005LNR6WG, the test leads are 50-ft. long. Megohmmeters are commonly used for electrical maintenance and testing in industries such as HVAC, transportation, manufacturing, mining, and utilities, among others.
Megohmmeters, also called insulation testers, are electrical test meters that measure resistance to the flow of current in an electrical component or circuit and check the continuity of an electrical circuit to detect electrical problems such as degraded insulation and improper circuit connections in equipment, wiring, and power supplies. Resistance is an indicator of the overall condition of the device being tested. Megohmmeters have an internal power supply, such as a battery or a capacitor, which supplies a test voltage to a circuit or component that is turned off. Test leads are connected in a series to the tester and the circuit or device being tested. The meter calculates the difference in voltage between the leads and measures the resistance. Most megohmmeters have two terminals for test lead attachment. The two-terminal, or two-wire, measurement method includes the resistance of the circuit or device being tested and the resistance of the test leads, and generally provides sufficient accuracy for measuring large values of resistance in insulation testing applications.
Fluke Corporation manufactures electrical testing tools and software for industrial and commercial applications. The company, founded in 1948, is headquartered in Everett, WA.