Just how good or bad can a $1.78 DT-830B multimeter from AliExpress be?

[james_s]

I've kept one of the free Harbor Freight meters in my car for years, it comes in handy every once in a while. They're fine for kids tinkering too, much better than anything I had access to when I was a kid, a digital meter like that probably would have cost $100 in the early 80s.

[Grandchuck]

Hickok DMM, 1970, $395.00

[J-R]

Of course these cost more than $1.78 to make and far more than that to ship; there is no free lunch.  The money comes from elsewhere.

[Zenith]

Are they any worse than the Japanese 1000 Ohm per volt analogue multimeters sold in the late 60s? I'm sure many of us bought and loved those. I think they did have a proper wafer switch. Mine does but it's a deluxe 30,000 Ohm/V version. It does have a separate 1.2KV input. I've never tried it and never will. Proper people would have had an AVO or Simpson, and wouldn't be seen dead with such a thing.

I believe these DMMs do their switch thing by contacting lands on the circuit board. They are value engineered. Copper dust builds up and causes problems, such as BANG!!!. Low voltages, continuity and it's silly to expect much else for the price.

[Zenith]

Of course these cost more than $1.78 to make and far more than that to ship; there is no free lunch.  The money comes from elsewhere.

The shipping comes from an international postal agreement which has gone on for years and which the Chinese take more than full advantage of. Of course it has to be paid for.

[Gyro]

I believe these DMMs do their switch thing by contacting lands on the circuit board. They are value engineered. Copper dust builds up and causes problems, such as BANG!!!. Low voltages, continuity and it's silly to expect much else for the price.

Most DMMs do these days, apart from some(?) Flukes.


EDIT: Check out some of Joe Smith's DMM robustness tests. The Agilents / Keysights are quite entertaining on switch wear!  https://www.youtube.com/channel/UCsK99WXk9VhcghnAauTBsbg/videos

[David Aurora]

I look forward to seeing these in the next Jaycar catalogue for $20 each

[Fungus]

On a related note: What's the best DT830?

Looking around, it might be this one:


Info: https://lygte-info.dk/review/DMMDT-830D%20UK.html

Aliexpress: https://www.aliexpress.com/item/1005005161813621.html

[NoisyBoy]

Since the 10A range is unfused with only a shunt, I wonder what would happen if it goes beyond 10A?  In the case of the HF meters, I afraid the probe wiring may act as the fuse, which can get ugly. 

The HF meters in the US is even more capable than the DT-830D+, as it can measure up to 750V AC, and 1000V DC!  If one is brave enough to try it with the provided probes.

[Fungus]

I've been trying to find Big Clive's other trashy meter but it's not easy to get hold of at a reasonable price. If I lived in the UK I could get one but bot here in Spain. :-(

Farnell sells them for about $4 but I have to pay 15 Euros shipping. Maybe I could buy a dozen and flip them on eBay for a profit, keep one or two for myself. 

https://es.farnell.com/duratool/d03047/multimeter-digital/dp/3498310

[factory]

Since the 10A range is unfused with only a shunt, I wonder what would happen if it goes beyond 10A?  In the case of the HF meters, I afraid the probe wiring may act as the fuse, which can get ugly. 

The HF meters in the US is even more capable than the DT-830D+, as it can measure up to 750V AC, and 1000V DC!  If one is brave enough to try it with the provided probes.

Or just make your own sticker up for it  , example below from the TEA thread;

I've spent too much time on this - especially for what it is.  Justification for efforts up to this point: Entertainment value for EEVblog members, but I have to wrap it up.

Artwork is done.  Just have to go through the production process.

David

[graybeard]

Of course these cost more than $1.78 to make and far more than that to ship; there is no free lunch.  The money comes from elsewhere.

It seems to be some sort of loss leader on the AliExpress iPhone app.   I do not see these deals on the web site.   You have to choose 3-10 of these "special" items and they claim you get free shipping.   Where I live I pay 10.5% sales tax, but Aliexpress adds about 18% for the tax.  I suspect some of that "tax" amount goes to cover the shipping.

When I bought the meter it was $1.78, but most times the offers are for $1.99, $2.99, or $3.99.   If you look at an image from the iPhone app today you can see the meter is $1.99.   I bought one of the $1.99 AppleWatch chargers for my wife and it works great.   



The meter I bought was defective, it shows a low battery all the time.   But you may get lucky and get a good one.  I have made for of these orders and "returned" three of the items as not described or defective.  Each time I am given a refund within a few minutes of requesting it.   The refunds are for the full price, bot the "sale price."    Look at the refund I got for the meter.  I paid approximately $2.14 with "tax" and was refunded $3.86, more than I paid.

[Paul T]

The variant of this meter shown in the lead post can be made adjustable for calibration. R8 is a 1K resistor. By replacing it with a resistance network that achieves a range around 1k, you can fine tune it while the leads are attached to a precision DC voltage source.  For instance, a 900 ohm resistor in series with a 200 ohm potentiometer.  I chose to use a 1.5K (18B) fixed resistor in the R8 spot, and a 5K micro pot in the empty space beside it, because it was handy and produced a professional result. When the pot is around 3K in || with 1.5K, 1K is produced.

[Paul T]

I took the time to add calibration so I could be precise with voltage readings for my 4-wire conversion.

By adding a powerbank charge board, tested good lithium cell from a e-waste GPS unit, and a LM317 constant current source set to 100mA, I am now able to make quick 4-wire checks on any number of things.  I have usb attachments to test cables, prong probes for PCBs and so on. The only feature I disabled was 10A mode.  The main unit functions on the 9V battery as usual.

The attachment shows checking a precision 100 milliohm resistor.  I just have to multiply the mV voltage reading by 10 to determine milliohms.

My point is these are not serious devices, but cheap enough to make inexpensive useful tools out of... so they are of some value.   All together I may have spent $3 on the meter and consumables, nothing else required a purchase except the test clips to make a 4-wire tester.  This meter and many others like it have plenty of room inside for extra circuitry for your application.