The advantages and uses of clamp meter
Most clamp meters have the first line electrical diagnostic testing function of a digital multimeter (DMM) and can also be connected to a circuit to measure voltage, current, frequency, capacitance, temperature, and resistance using test leads (as well as continuously test the circuit to see if there are any faults or missing components). It also comes with a set of specialized spring type pliers of various sizes, which can be clamped around wires or busbars for non-invasive current measurement.
Clamp gauges typically measure common AC and DC currents. The clamp meter for measuring AC power is mainly used for public use, while the clamp meter for measuring DC power is mainly used for measuring industrial AC/DC conversion motors, measuring battery DC power supply, measuring DC power supply used in electric vehicle systems, and measuring solar array DC cells. Although a multimeter can obtain a contact ampere reading of up to 10A using test leads, a clamp meter can provide safer and more non-destructive current readings in the range of up to 3000A.
Some clamp meters are single purpose pure ammeters that trade other functions for smaller jaws, higher resolution readings, higher sensitivity, and a compact overall pocket design. Other clamp watches will also have a "flexible clamp" flexible ring to replace the jaws. Long and flexible rings can be manually wound around crowded cables in the cabinet, which may be difficult to access using rigid pliers.
There are also some high-quality clamp watches that can provide better accuracy for more challenging work. The "true equivalent effective value" (root mean square) clamp can measure more accurate equivalent DC effective value when the current waveform is sinusoidal or non sinusoidal. When wires are bundled together, the induced coupling of current between the wires can lead to stray (or "ghosting") voltage, resulting in inaccurate readings. Using the "LoZ" mode can eliminate errors. If variable frequency drives (VFDs) are used in industrial sites, low-pass filtering mode "Lo Pass" can be used to improve measurement accuracy. Some models of clamp watches also use a built-in pointing non-contact infrared thermometer to measure temperature (point temperature gun). Some also use dual thermocouple inputs to calculate the temperature difference (Δ - T), which is essential for the work of HVAC/refrigeration engineering.
Advanced clamp watches with Bluetooth or METERLiNK can even stream readings to mobile devices through remote viewing applications for safer remote monitoring.
Application scenarios of clamp watches
Firstly, check the nominal overvoltage category (CAT) of the clamp meter to see where it can be used. CAT II instruments can be used for plug-in devices and appliances, while CAT III instruments can be used for fixed wiring inside buildings. The most stable category, CAT IV, is used for service panels and low-voltage outdoor wiring in utility companies. For safety reasons, potential job demands should always be considered and the best CAT nominal rating should be selected. Clamp gauges can measure the current load on circuit wiring and equipment, including motors, pumps, lighting, sensors, and switches. From DIY toolboxes to industrial maintenance tool carts, they can be seen everywhere.
