Review on OTC 3820 06 Low Amp Probe by Chris Elam

Without going into theory, I think this review is very necessary for this type of device. I fully understand and appreciate the level of misunderstanding about tools like this coming out of the automotive and trucking industries and my goal here is to help my fellow locksmiths by explaining that you really do care about your efforts don't have to waste. made such hard money *I returned mine after thorough inspection. I could not reliably measure a DC current of less than 100mA. Period. Most cars can't handle more than 50mA without destroying the battery in a day or two. Don't listen to the tool cart idiot trying to sell you a prettier version of one of those tool carts: he understands even less than you can fully appreciate as you read this. Trust me when I say that all of these devices are the same, as is true for such low DC currents. If you think you can use this to solve parasitic drawing projects, think again. Hall effect devices like this generally don't give you reliably low DC readings when all you want is baseball numbers. For the most part it works well on AC, but that's the nature of electricity. AC changes over time, DC does not. This device measures current changes caused by or generated by a magnetic field. If the current is stable and not very high, you're screwed. I have tested this tool on the Fluke 28 II (waterproof 87V), Fluke 115 and Keysight DSOX1204g desktop oscilloscope. I was ONLY able to get it to 10mA because I built it in a controlled test circuit where I already knew the current and B-field. Without knowing the number I'm looking for, I could never trust this one in the field for anything like 80mA, which is enough to kill most small cars or old weak batteries in one night. I would say that three or four out of ten attempts to carefully zero the probe before pinching the wire showed numbers that could be used. I really wanted to like that thing too. Trust me I tried really hard to make it work. Meet your expectations and you will not be disappointed. It accurately measures DC above 2A DC and is still useful for diagnosing the charging system, although I've never needed something like this to properly diagnose an alternator and I'm sure most of you haven't either, so make your decision what is right for you. If you're in the market for stuff like this, let me give you a suggestion: read more about using the fuse drop method to find pranks. Basically you take your DVOM in the DC mV range and go through each fuse looking for your draw. Black wire on one fuse arm, red wire on the other. The positive or negative number on the counter doesn't matter, just the distance from zero. Fuses that read 0mV won't blow, so move on to the next one. Fuses with non-zero numbers are circuits worth paying attention to. There are graphs to make this easier to understand as the mV drop value depends on the size and form factor of the fuse itself. Best of all, you don't have to pull fuses every time to find your move. This is a very neat feature for modern cars with 30+ modules on board that will spring to life if you accidentally wake up other modules on the network by pulling fuses with an old built in version of the battery disconnect ammeter leaving you chasing your tail for hours . .Save your money, read a little about how they work and why they can't be as accurate as what we want to test, and you'll have much more success with parasitic vehicles. I 100% promise you that the above method will make you work faster and more accurately than this tool or any other similar tool. Those are the facts, gentlemen. Much luck. Hope that helps.