AideTek VC480C Precision Milliohm Meters 4 Wire Kelvin Clip 0 Adjust Large LCD Backlit LCD Data Hold Manual Zero Display Adjust with Calibration Certificate

I'm quite happy with the AideTek 480C+. A Kelvin measurement technique is essential to achieve any kind of accuracy measuring below 10 ohms. This meter will be accurate enough with the right ranges for what I need to do which is general purpose testing of things like motor fields and armatures as well as other low resistance items. I did test several ranges against 1 percent resistors ranging from 3 ohms to 10 milliohms and the results were good. I also had no substantial drift problems with zeroing. I would suggest zeroing on the lowest range (20 milliohms) by placing the clamps on a clean short piece of #12 solid copper wire (or a similar scenario) with the clamps not touching each other and about a quarter inch apart. Just clamping one clamp to the other is not a good way to zero it because the clamps are polarity sensitive for one thing (source and sense). You'll get different results depending on which way the clamps are attached to each other. Zeroing the lowest range should result in all ranges being zeroed. Once the meter is zeroed the polarity of the clamps shouldn't matter for testing. The meter has a backlight that can be turned on and a hold function that can be activated. The display is quite large and easily readable. The leads are good quality. I haven't had the meter long enough yet to evaluate the lifetime of my 6 AA alkaline batteries that must be user supplied. A strap is included so that you could hang the unit around your neck or shoulder. There is no lead storage in the case so you may want to store the tester in the box it came in.

I bought this 2 years ago to see what you get for around $100. I was pleasantly surprised. Yes it is manual adjustment, no-frills instrument. You could adapt any decent meter with some external circuitry to do the same thing; but you would have to spend more than $300 in time and materials. (It would be a nice Arduino project, but what's the point -- you need to measure something.) I tried it with some precision low value resistors; it is accurate to its specifications. I meant to write a review at that time, but forgot. Fast forward to 2 years later after I left the batteries in the meter: I took it apart to try to salvage it from the damage done my negligence. The design is very nice and well thought out. It was easy to recover from my abuse. Did some spot checks to confirm that tolerances were still good. Then to the task at hand. A copper sheet that had been annealed (unprofessionally) needed to be measured to see if it was still electrically good. Should be 575 micro ohms. Measured 580 micro ohms. So I am very pleased with this product. If you occasionally have a need for low resistance measurements, this is the best instrument for the money. You probably want to make your own test leads to measure test points that are separated by more that 1 meter. Procedure: Null, measure, confirm null. It will drift; so always confirm null.

Works as promised

This is not a high quality meter but it does prove to be fairly sensitive. Build quality is ki d of like the toys you get with a kids meal but it works.

I ordered one of these but it was effectively DOA. I briefly got the calibrate knob to zero it (with the leads shorted), but then after a few minutes that quit working: the knob had no effect and the display read "overload" regardless of its position. Powering off/on did not fix it. Not only all that, but when I did get it to zero early on, it measured a 0.5% 15 mOhm resistor at over 20 mOhm, way outside its spec'd accuracy -- a completely useless result.Thinking I just happened to get a lemon (it happens), I initiated an exchange with Amazon -- which went great -- but guess what? The second one exhibited exactly the same symptoms! Somehow I was not surprised, however.I am a retired geophysicist and worked for decades in remote locations with instruments, sensors, and electronics of all sorts. I do know how to use a simple meter (and they shouldn't get any simpler than this one). It is not operator error. Nevertheless I did read the instructions several times to make sure I wasn't missing anything. Nope, they said to do exactly what I did.I returned the second one and am now patiently waiting for Amazon to credit me for two of them, whichis not an insignificant amount of money. I strongly recommend NOT buying these. They are totally worthless, a piece of junk. Buy one at your own risk, as they say.