To measure current “non-invasively” or for example to find a given lead in a net of other leads is an ideal task for a clamp meter.
Yes, in many cases it is possible (less or more laboriously) to disconnect the measured lead and to connect it into a series of a classic multimeter. It is even a more accurate measurement as there´s no risk of magnetic field influence but you´ll probably agree – it´s a far less comfortable solution and in many cases laborious, if not even impossible. On the other hand, to catch the desired lead into a clamp meter is usually a breeze – for example in distribution boxes or other, not extremely dense installations.
A clamp meter can be usually very helpful for example also in one relatively frequent requirement – for identification of a lead through which a known current flows. There are situations when we know that, for example, through one of 100 leads flows a known current but we don´t know which lead it is.
The clamp meter is absolutely invaluable when when searching for a cause of a too frequent RCD (residual current disconnector) switching off. Already a resolution of mA or tens of mA is usually sufficient to identify which lead is responsible for those “lost” tens of mA, and also which is responsible for switching off the whole section connected the given RCD.
TheVC-521 can replace a common multimeter as it´s able to measure voltage, current by means of jaws (even the DC!), frequency, duty cycle, capacity (already from nF), resistance, temperature, diodes and continuity.
A useful additional feature is also a non-contact detection of AC voltage (100-600V). User comfort is also increased by functions HOLD and REL. The REL function can serve for a classic measuring but also to null the offset at measuring of DC currents caused by a residual magnetism in the jaws - this can temporarily appear after measuring of high DC currents or also by influence of external magnetic field (magnet, loudspeaker, ...).
Plastic lug on one of the jaws is in fact a sensor for non-contact AC voltage detection. This lug also enables easier “separation” of a desired wire from other wires - for example at measuring in a distribution box. Maximum reading is 3999, what´s naturally better than classic „1999".
Basic specs of VC-521 can be found in the attached table