Uni-t ut18c Voltage and continuity tester teardown. Interesting design choices!

[JonnyM]

I just received my Uni-t 18c voltage and continuity tester from aliexpress. I'm an electrician so voltage and continuity testers are very handy and foolproof for troubleshooting and for proving that a circuit is dead.



Here's some pictures from my teardown:



Back side of L1 probe



The strain relief wasn't properly clamping the cable 



Fixed it!


Front side of L1, Two ptc's


Back side of L2 probe.


Front side of L2 probe. It uses a 32bit arm?? Isn't it quite overkill for such a simple device?

[WhichEnt2]

At least it doesn't have a trimpot inside, which being substituted by 2 parallel resistors like in the predecessor.

[T3sl4co1l]

ARMs are very cheap.  Might as well save on dev cost!

Tim

[joeqsmith]

I just received my Uni-t 18c voltage and continuity tester from aliexpress. I'm an electrician so voltage and continuity testers are very handy and foolproof for troubleshooting and for proving that a circuit is dead.

Wait, you're an electrician and you are using UNI-T products?  Even if you have to fix them from the factory as you have shown, that's a big endorsement as far as I am concerned.  With a probe like this, I assume you are working in industrial rather than residential, CAT III and up? 

[JonnyM]

I only work in residential areas. Mostly measuring single phase (230v). I haven't ever even needed to measure between two phases. The other option would have been the fluke t110 but my co-workers have had some troubles with them, same problem as this guy: https://www.reddit.com/r/electricians/comments/4qxzbk/fluke_t110_repair/

Here's some pictures of the fluke from the Reddit thread: https://imgur.com/a/KCnLq
It seems that it doesn't have any input protection at all or am I missing something?

[JonnyM]

ARMs are very cheap.  Might as well save on dev cost!

Tim

Good point, I don't think they produce that many, it's not a very popular product.

[joeqsmith]

Looks like only the one half of multiple meters is shown.   Too bad no one posted their findings.  Would have been interesting to know what the problem was. 

Are your co workers all using UNI-T products now as well? 

[JonnyM]

One went back to his fluke 177 and the other one got a Duspol branded voltage and continuity tester, very nice tool and probably robust but it costs 115€.