AN8008 US $19, 9999count, 1uV, 0.01uA, 0.01Ohm, 1pF resolution meter

[alm]

It's always a good idea to own more than one meter anyway, so that:

To me this meter (for low level measurements) plus a sturdier 3.5 digit meter seem like a sensible combination. You could use the other meter in case you would have to measure dangerous voltages, would need mA ranges or just would need a second meter. Oh, and when you need the relative function .

c) You can occasionally check meter readings against each other. If you see a weird reading, how do you know the problem isn't the meter? There's no substitute for a second opinion, even if you own a Fluke 87V (in fact I'd have more overall confidence in my readings if I owned two of these than if I owned a single Fluke)

This I do not understand. This is not because I think the Fluke 87V is perfect, but because I expect two meters with the same basic design and manufacturer to behave very similar. For example, if it had a design or manufacturing flaw that made it drift (or excessive temperature coefficient), that flaw may very well be in both meters. So I do not think having two of the same provides much improvement in confidence. In statistics terms, I expect the data from the two meters to be highly related, so averaging would gain very little.

On uA AC, mine was spot-on when compared with a Fluke 87V. Really, no more than 2 or 3 counts away in both ranges, right down to the smallest signals. That impressed me, to be honest.

I am pretty sure that the Fluke 87V has also its AC specs only apply for more than 10% of range or something like that. So I would not trust the 87V measurements at the bottom of its range either. It may just be that both are similarly off . The only way to compare is to measure something that is near full scale on the 87V, but near the bottom of a scale on the AN8008.

[Gandalf_Sr]

I ordered an AN8008 from Amazon 2 days ago for $22.59 which includes shipping.

I own several meters that are on my main bench but, as an EE designer, I now keep running into situations where very low (tens of nA) readings are needed and the small size means that I can add it into a workbench test setup without it overpowering the whole setup.

After watching Dave's video, I looked at the Fluke 101 and, while small, I can't see that it is worth the extra money.  Like others here I will test/calibrate the ranges I'm interested in - mainly low DC volts and current - against my Agilent U1252B and Keysight 34461A.

I will take the back off it to check for bad soldering and maybe replace a shunt resistor or two if I get poor accuracy but making custom daughter boards for it seems more effort than it's worth.

Has anyone looked at which components might be prime candidates for upgrades yet?

[Fungus]

c) You can occasionally check meter readings against each other. If you see a weird reading, how do you know the problem isn't the meter? There's no substitute for a second opinion, even if you own a Fluke 87V (in fact I'd have more overall confidence in my readings if I owned two of these than if I owned a single Fluke)

This I do not understand. This is not because I think the Fluke 87V is perfect, but because I expect two meters with the same basic design and manufacturer to behave very similar.

It tells you if one of them is broken. Meters break, probe leads break, meters get dirt inside them, etc.

You can also own different brands/models, that's OK. 

[Fungus]

Edit1: Reading the small print, that meter needs a weird 12V battery.

I have a similar unit, it uses a 12V battery, same used in many car remotes. Wouldn't call this an issue, but battery costs like half of DMM. I replace it every two-three years or so. It's only 2000 counts, but this is good-enough for most my purposes.

I think I know the one, it's used in garage door openers, etc. If you open one up it's 8 LR44 button cells in a plastic tube to get 12V.

I found a pic of that meter with the leads attached. It gives a better idea of how tiny it really is.

It looks quite well built for the price. I'm not imagining it's a good meter but it has a continuity buzzer (unlike most DT830B) and it might be $4-worth of fun to pull one out at Arduino club.

(the transistor tester kinda spoils the looks though)

[Muttley Snickers]

I interpreted alm's statement to mean that two same meters could both share a vulnerable or blind spot on a particular range, measurement or environment, using a different meter or meters to verify or compare against in my view would be a logical approach in the context of equipment that had not yet proven itself to be trustworthy.   

[Gandalf_Sr]

Ahh, so those little 12 volt batteries are just 8 LR44 button cells in a plastic tube eh?  My cottage garage door openers use those and they are expensive, I can buy 10 LR44s shipped from China for <$1 so it seems that buying those and adding some heatshrink might make for a cheapskate replacement.

[Fungus]

Ahh, so those little 12 volt batteries are just 8 LR44 button cells in a plastic tube eh?

Something like LR44s. Check actual size before ordering.

My cottage garage door openers use those and they are expensive, I can buy 10 LR44s shipped from China for <$1 buying those and adding some heatshrink might make for a cheapskate replacement.

Yep.

[Mark Hennessy]

On uA AC, mine was spot-on when compared with a Fluke 87V. Really, no more than 2 or 3 counts away in both ranges, right down to the smallest signals. That impressed me, to be honest.

I am pretty sure that the Fluke 87V has also its AC specs only apply for more than 10% of range or something like that. So I would not trust the 87V measurements at the bottom of its range either. It may just be that both are similarly off . The only way to compare is to measure something that is near full scale on the 87V, but near the bottom of a scale on the AN8008.

Yes:

AC conversions for Model 87 are ac coupled, true rms responding, and valid from 3 % to 100 % of range, except 400 mA range (5 %
to 100 % of range) and 10 A range (15 % to 100 % or range).

Most of my spot-checks on the uA ranges were not at the bottom 3% of the range, but those that were were fine. Fluke's specifications are very conservative

I've just double-checked with a 187 added to the series chain, which has a tighter spec, along with the BM235 (just out of interest); all good 

Still, I suppose that if you can measure AC millivolts well, it's not much of a leap to get to uA

[tautech]

Ahh, so those little 12 volt batteries are just 8 LR44 button cells in a plastic tube eh?  My cottage garage door openers use those and they are expensive, I can buy 10 LR44s shipped from China for <$1 so it seems that buying those and adding some heatshrink might make for a cheapskate replacement.

They're smaller than a stack of LR44's and there's a couple of common 12V sizes, the most common being:
23A 8 x 28mm
27A 10.3 × 28.5mm

https://en.wikipedia.org/wiki/List_of_battery_sizes

[Gandalf_Sr]

They're smaller than a stack of LR44's and there's a couple of common 12V sizes, the most common being:
23A 8 x 28mm
27A 10.3 × 28.5mm

https://en.wikipedia.org/wiki/List_of_battery_sizes

Thanks, glad I read this before ordering a container full of LR44s on a slow boat from China

[exe]

I'm not imagining it's a good meter but it has a continuity buzzer (unlike most DT830B) and it might be $4-worth of fun to pull one out at Arduino club.

Well, voltage readings were spot-on (+-1 count) after 8 years without any calibration (guess it's not too hard make an accurate 2000 counts DMM). Actually, after my own calibration it become worse . So, a totally usable device to me when resolution is not needed (most of the time for me). And yes, I used it on mains as well, although I hesitated holding it in my hands. But it did the job well.

[Alex Eisenhut]

Wow, that's too good to pass up. Ordered one. Of course this means I'll have to select something of my own to donate to a hacker/maker space.

[kalel]

They're smaller than a stack of LR44's and there's a couple of common 12V sizes, the most common being:
23A 8 x 28mm
27A 10.3 × 28.5mm

https://en.wikipedia.org/wiki/List_of_battery_sizes

Thanks, glad I read this before ordering a container full of LR44s on a slow boat from China

You can also check the prices of the original type in your stores and on eBay. They don't seem any more expensive than 9v.

[elfor]

This would be the perfect base for a cheaper EEVblog branded multimeter.

His official BM235 meter is a whopping AU$150.00, who knows how much that's in real money.

And it doesn't even come with a cool pouch! Doesn't that violate Australian law?

[SeanB]

Ahh, so those little 12 volt batteries are just 8 LR44 button cells in a plastic tube eh?

Something like LR44s. Check actual size before ordering.

My cottage garage door openers use those and they are expensive, I can buy 10 LR44s shipped from China for <$1 buying those and adding some heatshrink might make for a cheapskate replacement.

Yep.

Under 50c US retail here, and if I buy the Energiser version they are $1.50 each at Wallyworld. I buy them in strips of 5, and in a remote control they last around a year, just like the name brand ones. The expensive ones are the 7V5 5 cell ones that are used in certain remotes, or the CR1620 that car OEM fobs use, that are integrated into the key itself.

The A23 packs are a lot cheaper than a 9V pack here, which are at least $3 each retail, and if you want Energiser or duracell they will knock you back $5 or more each. You can get the OHL versions of the 9V brick, but they are more sawdust and air than active chemical, and are around the same capacity as the A23 pack in use. you really want to pay buy a PM3 brick, those are often over $5 for the cheapest ones, I got the branded radio which uses them for $3, no battery but I found a used 9V wall wart to power it instead.

[ocw]

Mine is better than yours here as well. I wonder if I'm lucky, you're unlucky... On uA AC, mine was spot-on when compared with a Fluke 87V.

Perhaps I rate current measurement accuracy in a different way.  Putting two meters in series makes the limitations of both meters influence the other.

I connect a 0.01% accuracy resistor in series with a voltage measured with 0.0015% accuracy and measure the current with a single meter to see how that compares with the current based on Ohm's Law.  That's what I call real world current.  Good meters are accurate without any correction required.  A current to voltage converter using a ADA4530-1 IC which I made doesn't need any correction.  I have tested it on measuring the current from a 1,000 volt power supply without having any problems.

I realize that $20 meters can't meet that standard.  However, we are at the point where maybe a $500, definitely $1,000+ meters should.  After making the above measurement, I correct it by taking the meter's shunt resistance into account.  That produces a figure which should at least meet the manufacturer's specifications.  But, if the meter is measuring a current which doesn't have a linear voltage to current relationship, it may be impossible to translate a measured current to the actual one.  The same is true if accurate voltage regulation is required.

While all of this isn't that important for a $20 meter, I still evaluate equipment the same way.  The manufacturers will keep making meters with compromised accuracy until meter reviews start measuring real world current which doesn't require you get out your slide rule to translate.

Back to the AN8008--while a 2 uA AC current measurement with reasonable accuracy is possible, 2 mA is not.

[Fungus]

I'm not imagining it's a good meter but it has a continuity buzzer (unlike most DT830B) and it might be $4-worth of fun to pull one out at Arduino club.

Well, voltage readings were spot-on (+-1 count) after 8 years without any calibration (guess it's not too hard make an accurate 2000 counts DMM). Actually, after my own calibration it become worse . So, a totally usable device to me when resolution is not needed (most of the time for me). And yes, I used it on mains as well, although I hesitated holding it in my hands. But it did the job well.

OK, I'm getting one. Just for the LOLs.

[kalel]

I'm not imagining it's a good meter but it has a continuity buzzer (unlike most DT830B) and it might be $4-worth of fun to pull one out at Arduino club.

Well, voltage readings were spot-on (+-1 count) after 8 years without any calibration (guess it's not too hard make an accurate 2000 counts DMM). Actually, after my own calibration it become worse . So, a totally usable device to me when resolution is not needed (most of the time for me). And yes, I used it on mains as well, although I hesitated holding it in my hands. But it did the job well.

OK, I'm getting one. Just for the LOLs.

Good luck. I'm sure you will be happy (considering the expectations, not much can go wrong).
If buying, check it on Ali, I see a really good price right now (better than eBay, but this changes every moment).

Still, it has some tough competition such as DT 383 for $4 with K-type probes included and temperature measurement (no battery stuff though) and the DT700D with a large display and no temperature or battery stuff. Going further with price, a lot of things appear, but then we're getting closer and closer to AN8002.

[Fungus]

Still, it has some tough competition such as DT 383 for $4 with K-type probes included and temperature measurement (no battery stuff though) and the DT700D with a large display and no temperature or battery stuff. Going further with price, a lot of things appear, but then we're getting closer and closer to AN8002.

Both huge compared the ANENG. 

[kalel]

Still, it has some tough competition such as DT 383 for $4 with K-type probes included and temperature measurement (no battery stuff though) and the DT700D with a large display and no temperature or battery stuff. Going further with price, a lot of things appear, but then we're getting closer and closer to AN8002.

Both huge compared the ANENG. 

True.



It's a bit huge. Who would have considered 830D to be huge?

Maybe it's similar size to this expensive UYIGAO? $10, that's almost AN8002 price league.

[Mark Hennessy]

Putting two meters in series makes the limitations of both meters influence the other.

Howcome? 

I connect a 0.01% accuracy resistor in series with a voltage measured with 0.0015% accuracy and measure the current with a single meter to see how that compares with the current based on Ohm's Law.  That's what I call real world current.

So how do you account for the resistance of the shunt, fuse, wiring and connectors?

I make no claims here - I just want to know how it compares to my existing meters...

[ocw]

Putting two meters in series makes the limitations of both meters influence the other.

Howcome? 

Instead of just the shunt resistance of the "tested" meter limiting the current, you will have the two shunt resistances in series limiting the current.  I want a meter which won't change the actual current when it is inserted.  The added shunt resistance will lower the current unless you are measuring a constant current.  I don't often measure that when I am using the meter for repairs or alignment.  That's when I want it to be accurate.

So how do you account for the resistance of the shunt, fuse, wiring and connectors?

The AN8008 has a 100 ohm shunt resistor (99 & 1 ohm in series) for measuring uA currents.  I don't use that figure when correcting for its insertion.  I use the 100.561 ohms which I measured across the AN8008's two terminals.  I add the resistance of any connecting wires if that is significant.  Similarly, while there is a 0.01 ohm resistor for mA/A currents on the AN8008, I use the 0.0301 ohms which I measured across its terminals.

I don't need to play these correction games when I'm using my ADA4530-1 current to voltage converter or my electrometers.

[boffin]

The AN8008 looks great except the two missing mA ranges.  Does anyone know if the AN8002 suffers from the same fault?

[Gandalf_Sr]

There was a young man named Kirchoff
Who said there's something I'm sure of
Two meters in series
Carry current the same as
Cos the current flowing onto one node is the same as the current in the other of

Caveat <I just got back from the bar> 

[stj]

The AN8008 looks great except the two missing mA ranges.  Does anyone know if the AN8002 suffers from the same fault?

take a look