The Extech MA620 clampmeter is compact and easy to hold. Whether you are performing amp readings in a heavy duty industrial setting or doing commercial electrical work, the 600 amp rating and ample 40mm jaw opening can accommodate most jobs, swallowing conductors up to 750 MCM. You can easily read the large, illuminated, dual display even in poorly-lit job sites. The 4-digit (6,000 count) readout is complemented by a bargraph display to simulate an analog display. You can operate the meter with one hand, having a thumb-dial selector that is ergonomically placed on the side. One important safety tool that is built in to the MA620 that provides convenience and safety is a non-contact voltage (NCV) detector. The detector quickly identifies the presence of voltage on live wires and alerts the user with a red LED indicator. This eliminates the need for a separate tester, offering users more value, added safety, and less toolbag clutter.
The heart of the MA620 is an advanced digital multimeter. You can select auto- or manual-ranging and measurement functions cover all types of troubleshooting over and above noninvasive current probe measurements: voltage, resistance, capacitance, frequency, duty cycle, diode and continuity tests. Even measure temperature with the supplied Type K bead wire probe. For better diagnostics and troubleshooting, you can use one of several one-button functions: press HOLD to freeze a reading on the LCD; MAX/MIN tracks and display maximum and minimum values (useful for blind measurements); and REL activates Relative mode for “zeroing out” the meter, useful for improving the accuracy of DC current measurements. It can be very difficult to make accurate current and voltage readings in industrial and commercial applications when electronic devices are present. Fluorescent lights, motor drives, computer power supplies, and other electronic systems can distort the AC waveform, making it hard for averaging meters to get an accurate read. True RMS uses a more advanced formula to adjust for this kind of distortion.