AlienTek DM40C New Multimeter with some benefits [DM40A - DM40B - DM40C]

[DaneLaw]

A new product from Punctual Atomic (AlienTek).
DMM with scope & signal.




Its a small unit at merely 140x83x25mm 260g with a 3.5" 480x320 IPS touchscreen but its quite feature-rich.








Promo prices in China seem to be from around 60 to 120$ depending on the model-variant & the accessory kit, while a basic DM40C with MP01 test-leads is 107$
(domestic Chinese sale prices not international prices)

[DaneLaw]

[tunk]

At aliexpress the prices start at around US$80.
Compared to similar products this seems to be maybe $20-30 too much.

Home page: https://en.alientek.com/Product_Details/59.html
Manual: https://en.alientek.com/download.html

[Aldo22]

Compared to similar products this seems to be maybe $20-30 too much.

But it seems to be quite nice as a DMM.
The cheapest version has 39'999 counts and ±(0.03%+5d) DCV Accuracy. AC Response: 10KHz.

[tunk]

A short intro, including a teardown. Looks like it uses a GD32F427.
https://mysku-club.translate.goog/blog/discounts/102513.html?_x_tr_sl=ru&_x_tr_tl=en&_x_tr_hl=en&_x_tr_pto=sc

[BeBuLamar]

It's so cheap. The specs is about the same as top of the line Fluke handheld DMM.

[S2084]

I got mine a week ago. I made a video.


https://youtu.be/TWQ6emMZALw

[coromonadalix]

oh the fluke yellow color ??   guess fluke may chime in ?  or block some imports ?

[DaneLaw]

oh the fluke yellow color ??   guess fluke may chime in ?  or block some imports ?

Many DMMs carry that "Fluke" like color scheme, and even plastic molding that got that dense fluke-like feeling/appreance.

Also from relative budget brands like "Victor / RuoShui" with older models like 70C. https://imgur.com/a/victor-70c-board-pictures-old-relaymeter-from-early-2010s-sub-40bucks-with-pc-conn-JwvLzlx

[BeBuLamar]

I guess they are not sold in the USA because if they were the US custom will seize them like they did with Sparkfun DMM's.

[S2084]

I measured the temperature drift of this multimeter, with a temperature difference of almost 50°C
0.1% resistor with unknown ppm/°C.... I tried to isolate it in a glass, but according to the thermohygrometer readings, the difference is still 0.4°C.... with unknown ppm, this can be significant
As a source of constant voltage I used a 1.5V AAA salt battery

According to this measurement, with a temperature delta of the multimeter itself of 46.8 °C, the temperature drift of the multimeter is:

When measuring resistances in the range of 600 ohm
8.55 ppm/°C, the error is +- 0.52%

When measuring DC voltage in the range of 6.0000 V
24.1 ppm/°C, the error is +- 0.51%
I can't evaluate these results, because this is the first time in my life I've bothered with such crap😁. But as for me, with a temperature delta of almost 50°C, an error of 0.5% is, without exaggeration, an excellent result.

[RAPo]

There is even a video stressing that the fluke colour is important 

oh the fluke yellow color ??   guess fluke may chime in ?  or block some imports ?

[RAPo]

My A version arrived today, after some playing also ordered a C version

[coromonadalix]

well the teardown  shows an un-soldered touch screen connector mm    is the fw contain touch  functions ??  or not     and this item exist under other names / brand

and  not sure if its the same hardware on all but software crippled  or have different dmm chipset


and we saw an 10khz bandwidth ??  witch is very low  ?


we need teardowns, mostly under the shield plate     loll

thks

[S2084]

I measured the bandwidth, the results are shown in the graphs...

[RAPo]

The scope is 10MHz bandwith (10 bit, time scale=100ns-50s.

The Signal gen is 1-50kHz for sine,swatoothand triangle and 100kHz-100MHz for square wave.

well the teardown  shows an un-soldered touch screen connector mm    is the fw contain touch  functions ??  or not     and this item exist under other names / brand

and  not sure if its the same hardware on all but software crippled  or have different dmm chipset


and we saw an 10khz bandwidth ??  witch is very low  ?


we need teardowns, mostly under the shield plate     loll

thks

[danno_cj]

This meter was released three months ago totally broken. Had severe issues with measuring resistance in circuit reading wrong values, beeping on diode mode caused by minor vibration and was affected by switching power supply nearby. Firmware updates fixed the problems with beeping and resistance by adding online and offline. The first units came without shield on back case and now they have the shield glued. I don't know if cured entirely the interference or only improved by large degree.
Under metallic shields on PCB:
DMM side:
hy3131 dmm chip
TC1746B6 precision resistor network divider
MAX6190 AESA reference 5PPM  (outside of shielded area)
Osc side:
HCF4051 8channel analog multiplexer/demultiplexer
3PA1030 10 Bit 50MSPS ADC
What is strange is the presence of BT hardware but without mentioned in specs. It could be added later as feature or maybe is related with calibration.

[coromonadalix]

could be for the bluetooth 
or this pup is sold under other names / clones with more features, and maybe finding some fw in the future could unlock more things ??

[bobocher]

There is an update adding Bluetooth support:

2.1 update log (2025-03-24):
1. The multimeter adds Bluetooth function (currently only supports Android version, IOS version is under development), please be sure to refer to the manual!
2. The multimeter fixes the bug that causes resistance measurement errors due to gear shifting;
3. The multimeter fixes the bug that large capacitors cannot be measured in some cases;
4. The multimeter fixes the bug that the trend chart displays errors in some cases;
5. Some abnormal situations of the oscilloscope AUTO function are fixed;
6. Fixed the abnormal touch bug in some cases;
7. Support JPG format boot LOGO, resolution 480*320, name logo.jpg;
8. Change the boot mode to short press the power button to boot;
9. Optimize the display of the progress bar during charging;

This update is currently available only through Chinese version of the alientek web site. The files are hosted on baidu.com and require a baidu account, which isn't easy to get. It would be great if someone having baidu account could reupload the files to more accessible hosting.

https://pan.baidu.com/s/15ScThoPTyD-jJ3ulRLjHjA
Password to access this link: o59e

[lycreturn]

This is the DM40 V2.1 firmware and user manual

[Taimer81]

I measured the temperature drift of this multimeter, with a temperature difference of almost 50°C
0.1% resistor with unknown ppm/°C.... I tried to isolate it in a glass, but according to the thermohygrometer readings, the difference is still 0.4°C.... with unknown ppm, this can be significant
As a source of constant voltage I used a 1.5V AAA salt battery

According to this measurement, with a temperature delta of the multimeter itself of 46.8 °C, the temperature drift of the multimeter is:

When measuring resistances in the range of 600 ohm
8.55 ppm/°C, the error is +- 0.52%

When measuring DC voltage in the range of 6.0000 V
24.1 ppm/°C, the error is +- 0.51%
I can't evaluate these results, because this is the first time in my life I've bothered with such crap😁. But as for me, with a temperature delta of almost 50°C, an error of 0.5% is, without exaggeration, an excellent result.

Please tell me how the calibration is performed. Is it internal, and is it open to the user, or do you need external software, and it is not available for the user? Thank you.

[S2084]

New firmware version and android application

https://t.me/S2084K/24367

[Aldo22]

I would almost buy it, as I'm interested in the specs of the DMM.
But I really don't need the 50MSa/s oscilloscope and the 50kHz signal generator.
Does anyone know of a 40000 counts/ 0.03% DC accuracy or better DMM, for $60 or less? (No scope, no SG).

[RAPo]

I had the same thoughts initially.
But I bought the A version. After five minutes of play, the order for the C version was out.
If you have the money, try it.

Your question is a tough one. I don't have the answer.

I would almost buy it, as I'm interested in the specs of the DMM.
But I really don't need the 50MSa/s oscilloscope and the 50kHz signal generator.
Does anyone know of a 40000 counts/ 0.03% DC accuracy or better DMM, for $60 or less? (No scope, no SG).

[Aldo22]

I had the same thoughts initially.
But I bought the A version. After five minutes of play, the order for the C version was out.

Thanks!
What exactly are the differences between the A and C version?
I only see the DMM counts (40k vs 60k) and a few details. The accuracy is the same and so is the scope/SG.
But the C model costs almost twice as much?
Is there anything else?