I'm a novice in this field but I've been researching DMMs the past few days to eventually buy a nice one for general use. My use case is mostly general home maintenance and being able to also use it for circuit boards would be a big plus.
I would have already bought the BM786 if it had LoZ implementation parity with Fluke. The Brymen offerings just seem better in every conceivable way and are more fairly priced. In my research though, I happened upon the following article & video describing when LoZ is commonly used:
https://techcircuit.org/how-lowz-works-and-why-its-useful/#google_vignetteThey're both great demonstrations if you aren't familiar with the LoZ function.
Not to bury the lead here, Fluke implements LoZ with what appears to be a simple ~3Kohm resistor whereas Brymen implements it (in the meters that have it) as a 1Kohm + 1.2PTC thermistor which effectively creates a 2.2Kohm initial resistance that ramps up to a few hundred Kohm as current passes through. The added complexity of the Brymen implementation seems to add extra limitations on the input voltages and frequencies it can meaningfully read (>12V & between 50-400Hz). Additionally, I have concerns that Brymen's more complex implementation would be an annoyance/hindrance when dealing with LoZ use-cases beyond ghost voltage, such as current leakage and compromised voltage sources. For the latter would I only have 1-2 seconds of pre-ramp-up time to troubleshoot those events? And would I have to wait for the thermistor to cool down before getting the ~2.2Kohm impedance again for another 1-2 seconds? Many of Fluke's implementations also include a LoZ capacitance mode which is cool but a bit niche and not really important for my use-case.
I wonder if this is an instance where the simplicity of Fluke's implementation made for a more versatile function. Sure the Brymen LoZ provides some extra convenience for ghost voltage readings, but did it come at the cost of greater versatility?
To me, the LoZ function seems really handy for residential electrical troubleshooting. I want my chosen meter to have this function for that reason. Are my concerns with Brymen's implementation warranted? Or maybe I'm giving Fluke's implementation too much credit and the perils of a simple resistor outweigh the greater versatility I'm attributing to it? (possible risk of upstream circuit damage if not careful which the Brymen implementation gives some protection for)
And overall which do you think is the better and more versatile LoZ implementation: Fluke's or Brymen's? I suspect personal preference and use-case will weigh heavily here.
Thanks for reading!