Uni-T UT-D07A Bluetooth adapter for UT181A, UT171A, and UT71E multimeters

Some time ago, I bought myself a Uni-T 181A multimeter and thought then that the only thing missing from the complete setup was a Bluetooth adapter. I got one as a New Year’s gift, and today I’m going to tell you about it.
Unfortunately, it turned out that things aren’t quite so straightforward. More on that in the review...


This won’t be a very long review, since for the most part this adapter is simply a wireless version of the multimeter-to-smartphone interface. It also works with only a few instrument models.

It arrived in a small white box. Besides the adapter, the package includes a manual and a warranty card.


The only useful information is the manufacture date on the warranty card. The manual is entirely in Chinese, a language I know slightly less than not at all.


But since the company itself is fairly large, I was able to find an English version of the manual on the manufacturer’s website without much trouble.


I wouldn’t call the adapter particularly compact.


Though, to be fair, my main complaint is really about its thickness. More on that later.


There are two indicator LEDs: one for the connection (slow flashes mean no connection; rapid flashes mean it’s connected). It’s blue. The other indicates a low battery and is red.
The power switch is above them, recessed deeply enough that you won’t turn it off by accident.


On the bottom are the guides for fitting it into its designated slot, along with the data-transmission LED and photodetector.


It runs on two AAA batteries. I haven’t measured its power consumption, but I’ve been using it from time to time for about a month now, and so far everything’s fine.


It fits into its designated slot without any trouble. By the way, I’ve only just noticed that the Uni-T 61E has a cover for the adapter port, while the 181A doesn’t.


It doesn’t get in the way, and comes off fairly easily with a noticeable click as the latch releases.


But it’s awkward to set down on a table—that’s really my complaint about its thickness. Basically, the top of the multimeter rests on the adapter.


That’s why it’s much more convenient to use with the stand. The photo might make it look like the stand is pressing against the module. It almost is, but in fact it doesn’t touch it.


Since I have two instruments from this brand, I naturally tried it with the popular Uni-T 61E as well, but that ended in disappointment.
First, the adapter isn’t mechanically compatible with the instrument. You can install it, but it takes some forcing (literally, with a creak), and as you can see in the photo, the adapter’s casing ended up splitting in two.
They’re also incompatible both in hardware and software. It’s worth remembering that the 61E comes with an adapter for a COM port, while the 181A uses USB. The software is different too, and the programs aren’t interchangeable.


The Uni-T 61E with the adapter installed looks even funnier sitting on the table. You could even skip the stand :)


All right, enough fun. Let’s move on to the tests.
First, I found that the website has two different pages describing the very same adapter. One says it supports iOS and Android, but its download page only has a RoHS compliance document. The other page lists Android only, but does include links to the English manual and software.


Originally, I planned to use it with both my phone and computer. What’s more, the manual even says it works with Mac, Android, and Windows, though some systems might be added at some point (that’s a loose translation).


Fine, Android it is. And that’s where the second snag came up.
First I tried it with my Doogee X5 MAX, but unfortunately all I could get was a few readings before the connection dropped.
All right, I tried my wife’s Samsung. It works, but I had to connect and disconnect several times before it would pair.
Actually, it didn’t happen quite like that. I tried every “Chinese” phone in the house, and not one would work with the instrument. Then I tried the Samsung, and after a few attempts it finally connected. After that, I went back to my Doogee and managed to get it to receive at least something.


Well, I thought, that’s it. One last attempt: I grab the Lenovo P2 and find that it connects to the multimeter without any problems and works with it as if it were made for it. That's why the screenshots from here on are from the Lenovo.
In this photo and the previous one (with the Samsung), it might look as though the readings on the multimeter and smartphone screens just happen to match. They don't: in 9 out of 10 photos, the readings match. That's because there's very little delay between the multimeter and smartphone screens updating.


At first, I tried connecting the adapter the usual way through Android. That's no problem, and it doesn't even need a password. But then I found out that not only is this unnecessary, it can actually interfere with the app. You can even turn Bluetooth off on your smartphone; the software will turn it on by itself :)

I install the manufacturer's app and launch it. Once it loads, it asks which multimeter I want to connect.


The app's main window then opens. To connect the multimeter, click Connect, then Scan, and select the Bluetooth adapter.


A few seconds later, the multimeter is connected, and rows of numbers start streaming across the screen.
In this mode, data comes in at about 9 readings per second, which is pretty fast. In some modes, the time display shifts slightly, though this happens in Datalogging mode.


Turn the smartphone 90 degrees and the readings fill the screen. Though, if you ask me, they could have made the numbers bigger.


In the display mode with maximum/minimum readings, those are shown on this screen too.


Double-tapping the main screen brings up the controls. Essentially, this emulates the multimeter's four corresponding buttons. The Select button only works when the meter's selector is set to a range with additional functions.


Swipe across the screen to switch to the extended mode. Besides the standard options for saving and viewing saved data, it also controls the meter's additional features. In effect, we're looking at a virtual keypad for the multimeter again.


There's also a separate Datalogging mode, but I never figured out how it differs beyond the update rate. All its functions are identical to those in the previous real-time display mode.


Last is the mode for working with the standalone data logger. It all sounds good, except I couldn't get this function to work properly.
When you activate this function on a computer, the multimeter beeps briefly while the software retrieves all the saved readings from the meter's internal memory. Here, the multimeter beeps a couple of times, and that's it.
The only options are Save and Delete, but what to save or delete is a mystery. The meter's memory wasn't empty, of course; I even checked just in case, but no luck.
I wouldn't say I need this function on a smartphone, but the whole thing feels a bit half-baked.


And of course, here's a demonstration of all this. Though the video accidentally misses the extended settings menu—I somehow forgot about it while filming :(


To sum up, the adapter does work, and some things are even convenient, but not all the features work as they should. The range is perfectly adequate; it works reliably across a large room.
My biggest complaint is that the app is extremely picky about the smartphone model. As I mentioned, the software only worked properly for me with the Lenovo P2. The Samsung worked after a few attempts, while the relatively obscure models either don't work at all (which is more common) or, like my Doogee, load a few lines and then stop.

So, that's this rather mixed bag of an adapter.
That's all for now. As usual, I look forward to your questions and comments, and I hope you found the review useful.