These days, if you are in the market for a capable digital voltmeter, you might as well consider getting one with an oscilloscope built-in. One choice is the Owon HDS160, which [Kerry Wong] covers in the video below. The model is very similar to the HDS120, but the multimeter in the HDS160 has more counts–60,000 vs 20,000 as you might expect from the model number.
The internal chip is an HY3131, which is rated at 50,000 counts which is odd since the meter is 60,000 counts, but presumably the meter uses some capability of the chip, possibly putting it out of spec. The oscilloscope is the same between the two models. Almost everything else works the same, other than the capacitance measuring feature, as the video shows.
The difference in cost between the two units isn’t much, so if you are shopping, the small extra cost is probably worth it. Not that a 20,000 count meter isn’t perfectly fine for most normal uses.
[Kerry] really likes scopemeters. He gets excited about bench scopes, too.
Or they could be outright lying. That’s kind of least hypothesis here.
That’s kind of difficult to lie about on a meter because it has a direct effect on the digits displayed, the resolution, when ranges change etc so it should be really easy to check.
HY3131 has a SPI interface to some external uC. It certainly does not have a display driver for a high-resolution display as used in the Owon. Sniffing this SPI bus is quite easy, but it does take some effort. The additional uC could fudge the numbers. Do some scaling and filtering.
Looks like Keysight U1282A (An EUR 750 meter) also uses HY3131 and this is also a 60k count meter. This makes it more likely that the 60k count is some feature of the HY3131, but the difference is quite curious.
I strongly doubt Keysight would lie but I do wonder if there’s some processing trickery going on with the data from the HY3131
The first ADC in the HY3131 is 24 bits. So, we could call this 16 million count meter. But the effective number of noise free bits is certainly less than 24. Normal practice with ADCs like this would be average of filter the raw data and to use only some of the most significant bits of the output.
They are probably not quantizing the data quite as much as was assumed when the chip was called at “50,000 count” meter.
i’m sure there’s people who love having a portable scope or one with a fully-isolated ground. but i think a lot of the demand for these, especially the cheap ones, is people who want to buy just one inexpensive tool to check all of the boxes. anyways, that was me years ago.
and i found it to just be a generally infuriating user experience. after years of fighting with its sponge buttons and deeply nested menus, i happened across a youtube video of someone adjusting the x/y offset and scale by turning a dedicated knob and my mind was blown. i got a “cheap” $300 bench scope and it’s a totally different tool. i use it more often because it’s easier to use.
and on the other side, i got frustrated with my cheapo meter and i bought the entry level fluke meter (which cost more than this OWON unit) and it’s just a marvel to have a physical mode select knob. not sure paying extra for a fluke was worth anything but it categorically does not have the flaws of the meter before it :)
Having a bench scope that I enjoy I got one of those battery hand held ones as an extra. Its cheap, porta le, isolated, boots quickly … no, I would not use it for lpng measuring sessions. Bit to quickly check sometjing? Perfect.
Same with multimeters. O got a bunch, from those 5€ ones to a proper fluke and even a GW1.21. If im not sure ehat to expect? Lets use the cheapy in case it gets blown up …
hahaha my one complaint with the fluke is it’s still possible to forget the probes are connected for current mode when i’ve turned the knob to voltage mode. so far its protection circuit has done an admirable job and i have simply gotten lucky with the loads i’ve shorted out. knock on wood.
and that’s the only time i’m worried about blowing up my meter..
you’re giving me an idea…maybe i should get a $5 meter and use it exclusively for current measurements (which are much less frequent in my life)
I was an aide at my College Auto tech course. One of my tasks was putting 3A inline fuses in the Fluke test leads. The stock plasma safe fused were $15 each and they blew out a lot as the students worked.
Personally I think a different high-vis probe for current might make more sense (pun intended). Maybe even give it a different (triangle?) shaped handle to help you remember which measurement you are taking.
I keep a third yellow banana plug to crocodile clip connected for current measurements.
I love mine, I think if I were to buy everything from scratch, I’d get one of these and a cheap pen type multimeter for convenient low precision stuff, although I wish the pen meters were just a bit more advanced.
It is of course somewhat annoying to sift through menus all the time, but it’s not like I’m using it all that often, most of the measurements I need to make are just basic voltage or resistance measurements.
But then again, I’ve never owned a full size bench scope, I’ve just used them a bit at work, maybe if I spent more time with them I wouldn’t want to go back.