Extech MA445 True RMS 400A AC/DC Clamp Meter with NCV

I did not have a clamp meter for home use previously but have used current clamps in the past at work for measuring inrush currents and current draws on power supplies which were done using multi-thousand dollar Tektronix equipment. And while I haven't compared this clamp meter to a reference like that there are videos of others doing similar things on youtube that show how accurate these little meters are. This one is set apart from most others in that it will measure DC current and temperature which not all clamp meters will do and I wanted an all-in-one solution to replace my circa 1980's Micronta true RMS multi-meter.It is nicely built with a solid feel and a good albeit single line display. Ergonomically it has nice graphics with good legend contrast except for one area. The rotary switch. While the action of the switch has great feel with firm detents for each position and a nice knurled and rubberized outer ring it has a position indicator that is a short pointer bar recessed into the top of the green part of the switch. It is very difficult to tell what it is pointing to unless you have good light. I'm sure Extech decided that the tooling and manufacturing cost of having of a double-shot version with a high contrast indicator would be too much for the price point they were shooting for on this meter. As compromises go this is a good one in my view.Functionally the meter has everything one is likely to need and for home use its accuracy is more than adequate. AC voltage and current readings are true RMS with crest factor adjustment percentages listed in the manual for those who want to measure non-sinusoidal waveforms and who care about such things.I had an issue recently with my heat pump. The service technician had a Fluke clamp meter and I though this would be a good opportunity to compare the Extech to the much more expensive Fluke. So we measured the current of the compressor motor and both meters read essentially the same (within a 100mA of each other) on a 12A reading. We did some voltage readings as well and found those to be virtually identical. Not bad!Over the last couple of months since I received the Extech MA445 I've measured precision resistors, film caps, temps, line frequency, diode drops and tried out the NCV function. Everything works accurately and as advertised. Couldn't ask for anything more considering the very reasonable cost.

Bought this to look at DC current draw in my cars, as suggested by the photo on the package. I think it will serve my purpose well. It also has lots of other functions that I am sure to enjoy.My DC current measurement tests so far suggest it will allow me to read down to 10, 20, or 30 mA or so. That's basically what it's spec'ed at (about +/-2% +/-3 counts - which is about +/-30 mA when currents are small). Pressing and holding the zero-button worked well, bringing the reading to 00.00 or 00.01, ... Then opening the clamp and putting it on a wire carrying 100 mA (according to a through-measurement Wavetek meter), showed 00.13 of 130 mA. This will change though depending on how you move the loop head around to some extent. I think it depends on external B fields in the environment, which is a physics and environment issue, not an issue with the meter accuracy. Larger currents are fine. A 1.00A direct-measured current read 1.01A with the MA445 (very impressive for a clamp-on meter!)But if you move the meter very far after cal, you could get shifts of up to 0.05A or more - just depends on the magnetic field lines in the area.I also tested it on a few other functions:DC voltage of 12.00 V was spot-on at 12.00VResistors of 22 Ohms, 10K, and 4.7M read within their tolerances and the auto-ranging speed was good.Temperature read within a few degrees of what my wall-hung units showed in the house.And the non-contact voltage thing seemed to detect which side of the outlet was hot (after I figured out where the sensor actually is ;-) I personally would never use this for deciding if power is present or not !The meter is very nicely built and all functions I've tested so far work very well (reading the manual helps to resolve things like why doesn't the backlight come on etc )In short - its exactly what I expected and more. Nicely built and works well (within the limits of these tools). Definitely worth the price (and even a bit more maybe !)