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

[kalel]

I just checked eBay and this is what I get for delivery estimate:



(I got a tracking number, woohoo!)

eBay stuff's been taking 2 to 3 weeks to arrive recently. Maybe it'll be here next week. 

Awesome. Be prepared to share some photos. 

[plazma]

IIRC it requires editing I2C ROM content. Then UART TX is enabled. I planned to add an optocoupler and a cheap CP2102  board. Also range and delta buttons would be good.

Do you get access to the TX-pin on AN8002? It's easy to enable TX on the VC-921, but the TX-pin is not visble on the AN8002 as far as I know.

Looks like the TX pin is not wired. I got the pin visible and edited the I2C ROM. No signal.

[Mark Hennessy]

Mine arrived today. Ordered 1st July.

A few months back I picked up an AN8002, and have been quite impressed with it. But this is even better. This is a bit of an 8002-8008 comparison review, useful to anyone who already has the AN8002

If you don't already have either, it's worth mentioning that the case is hard plastic - no holster or similar. But it's light and seems to bounce well enough. A bit slippery on a hardwood bench. I much prefer the red of the AN8008 to the murky blue of the AN8002.

The AN8008 came with a bunch of accessories. The AN8002 didn't, but looking now, I see that they often do (though it adds a couple of £ to the price).

I can't image what use the square wave output will ever be. The AN8002 has temperature instead of square wave out, which is probably more useful. The square wave is fixed at 3V pk-pk. I haven't checked to see if that changes with battery voltage yet, nor have I tried to determine the source impedance and Zout is around 2k. It appears to be AC coupled, or at least, it's symmetrical either side of 0V.

The AN8008 has a manual ranging button - the AN8002 lacks that (unless you take it apart).

The millivolt ranges are better than most - 10mV and 100mV. Resolution in the 10mV range is 1uV, which is very impressive for a hand-held DMM, let alone one so cheap. Looking at my Fluke collection, you need to stretch to a 187/9 for that.

Away from mV, the lowest Volts range is 1V (0.1mV resolution). For comparison, the AN8002 does 60mV (10uV resolution) and 600mV (100uV resolution) in mV, and the lowest range in Volts is 6V (1mV resolution) - the same as an 87V in normal mode.

They've fixed a minor "bug" that the AN8002 has. When pressing the yellow button in Volts mode, the modes are DC, AC, Hz and % - but according to the silk-screen, it's only DC and AC. With the AN8008, the silk-screening shows all 4 options. Not a big deal, but at least someone was paying attention to detail there...

The AN8008 has uA. The ranges are 100uA (10nA resolution) and 1mA (100nA resolution). The Fluke 87V can do 10nA resolution if you put in in hi-res mode. The Brymen BM235 only does 100nA resolution.

The AN8002 lacks uA. The milliamp range has 10uA resolution.

Both have a separate jack for 10A. The AN8002 shares the main Volts, etc, jack for milliamps. In the case of the 8008, the 10A jack also does milliamps, and the main Volts jack is used for microamps.

In A/mA mode, there are 2 ranges: 1000mA (100uA resolution) and 10A (1mA resolution).

The AN8008 uses a separate ICL8069 voltage reference IC. No sign of anything like that in the AN8002 - presumably using a reference in the main IC?

I've initially compared the two models to my BM235 and 87V, using various DC voltage references, and the accuracy of both seems to be very good indeed. Will be interested to see if they hold their calibration over time.

I've not had a chance to do more detailed testing, so those are first impressions only. Forgive any errors - it's late!

For £15 delivered, it's astonishing.

All the best,

Mark

EDIT: Link to what looks like the OEM: http://szzotek.com/en/col.jsp?id=144

[ocw]

I received my AN8008  today.  It was ordered on June 29 from http://www.ebay.com/itm/282496420913 

I just made some quick accuracy tests.  The first attachment shows 10 volts from my upgraded AD688BQ voltage reference feeding both the AN8008 and my 34401A.  The second attachment shows the 34401A connected to the AD688BQ the same way and the AN8008 connected between the AD688BQ's negative 10 and positive 10 volt outputs.  The negative voltage from the AD688BQ precisely matches the positive voltage.

The shunt resistance of the AN8008 was 100.561 ohms when the meter was in the uA position and 0.0301 ohms when the meter was in the mA/A position.

Also attached are pictures of the meter's square wave output.  I included both the lowest (50 Hz) and highest (5 kHz) frequencies as well as the 500 Hz center frequency.

I'll complete my accuracy tests later.

[kalel]

Neat images guys. Good to know about the accuracy too.

About the "True RMS" thing written, is it real or is it there just to look nice?

It seems they like to add it on a lot of meters, including this sub $10 one:

[crazyguy]

Neat images guys. Good to know about the accuracy too.

About the "True RMS" thing written, is it real or is it there just to look nice?

It seems they like to add it on a lot of meters, including this sub $10 one:

It is real, all these cheap DMM are based on Hycon HY12P65 DMM chipset.

datasheet
http://www.hycontek.com/wp-content/uploads/DS-HY12P65-EN.pdf

T-RMS Bandwidth ~ 1.5kHz

[kalel]

Thanks crazyguy, good to know it's real for better AC reading.

[floobydust]

It is real, all these cheap DMM are based on Hycon HY12P65 DMM chipset.

datasheet   http://www.hycontek.com/wp-content/uploads/DS-HY12P65-EN.pdf

T-RMS Bandwidth ~ 1.5kHz

Neat multimeter IC and.. it has UART pins...

AC measurement bandwidth is lower than I thought:
AC sine wave 0.5% error 20-1,500Hz and -3dB at 6kHz.
Square wave 0.5% error max. 100Hz
Triangle wave 0.5% error max. 1.2kHz

But the IC's filter settings can maybe tweaked in app firmware to do better.

[Fungus]

I received my AN8008  today.  It was ordered on June 29

Mine arrived today. Ordered 1st July.

 

[tronde]

Neat images guys. Good to know about the accuracy too.

About the "True RMS" thing written, is it real or is it there just to look nice?

It seems they like to add it on a lot of meters, including this sub $10 one:

Spend some time here:

https://www.eevblog.com/forum/testgear/hacking-the-victor-vc-921/

As you can see from the images AN8203 and VC921 looks slightly different. Don't know about the internal of the AN, but you can find some useful info around regarding the VC921. If you stay away from mains, it is certainly worth the price. Especially if you hack it and enable serial out and 6000 or 8000 scale lenght. Seems like the Chinese have come up with some really interesting chipsets for small money.

[deflicted]

Anybody measure the open circuit voltage in diode test mode yet? Neither the eBay listings nor the specs on the Zotek site seem to give a value for that.

[ocw]

Anybody measure the open circuit voltage in diode test mode yet? Neither the eBay listings nor the specs on the Zotek site seem to give a value for that.

The diode test voltage is 3.223 volts.
The short detect voltage is 1.0070 volts.
The k ohm resistance measurement voltage appears to be the same 1.0070 volts.
The M ohm resistance measurement voltage is 0.5309 volts.

[ocw]

The M ohm resistance measurement voltage is 0.5309 volts.

I was going too fast on that one--the M ohm resistance measurement voltage is also 1.0070 volts unloaded.  I forgot to use my high impedance electrometer for that...

[deflicted]

The M ohm resistance measurement voltage is 0.5309 volts.

I was going too fast on that one--the M ohm resistance measurement voltage is also 1.0070 volts unloaded.  I forgot to use my high impedance electrometer for that...

Thanks. I was kind of scratching my head about that, wondering why a DMM would output a lower voltage for a M ohm range than for a k ohm range. I don't know enough to know whether or not you'd expect that in a DMM, but it seemed counterintuitive.

[RedSky]

How noisy is the meter when measuring microvolts?   say shorting the leads what does the display read?
I'd like to see the accuracy comparison with a high end bench or hand held multimeter at the microvolts level.  I mean i'm not expecting much considering its a $20 meter, but a bit of fun to see.

[ocw]

With the talk of True-RMS validity and accuracy I considered a good way to verify that feature.  I thought that the simple way with a known result would be to measure the RMS voltage of a square wave.  I chose a 3 volt peak-peak square wave.  It has a computed RMS value of 2.1213203 volts.  My measurements were:

                                   V        % Error
Agilent       34401A    2.12037   -0.04
Keithley      2015       2.1197     -0.08
Keysight    U1252B    2.1208     -0.02
Aneng       AN8008    2.112       -0.44
Uni-T         UT210E    2.112       -0.44
Uni-T         UT61E      2.1233      0.09
Mastech     MS8218    2.1216      0.01
Fluke            96B       2.120       -0.06
Fluke             77        2.331        9.88
Circuit Sp   CSI2010    2.35        10.78
RShack      22-186A    2.373       11.86
Triplett         60          2.14         0.88

I think that I can spot the meters without True-RMS.  But, check out the reliable old Triplett 60 analog meter.  Not bad!

Based on the readings above, is the Aneng AN8008 using the same IC as the UT210E?

Shorting the input jacks produces the following readings:

0.000 mV DC with a rare jump to 0.005 mV (nothing in-between)
0.000 mV AC
00.00 ohms
00.00 to 00.01 uA DC
00.00 uA AC

The above is with a 2 cm wire between the input jacks.

[ocw]

I'd like to see the accuracy comparison with a high end bench or hand held multimeter at the microvolts level.

The AN8008 uV accuracy is limited due to it just having 1 uV resolution.  I can easily make mV comparisons:

34401A              AN8008
2.4689 mV         2.477 mV  (2.476 - 2.478)
4.9503              4.957
7.4172              7.423
9.8978              9.902

Those are actually uV readings with the most resolution possible--not bad.
Additional tests later.

[RedSky]

Shorting the input jacks produces the following readings:

0.000 mV DC with a rare jump to 0.005 mV (nothing in-between)

Thanks for doing those tests, much appreciated.

I believe this is the first meter that I know of that can read down to the 1uV level less than around $100, apart from the Holdpeak HP-770d (which there isn't much information about around and dubious on the quality front) for $20 it's a bargain.  Mind you those meters up around the $100 range are of course 50,000 count as well, which this isn't.

0.33% off your 34401A at worst on the mV level to 3 decimal places is impressive for a meter this cheap.

Looking forward to seeing if my unit (still on it's way) is this accurate, could be a very useful little meter.

[ocw]

I give the AN8008 an A+ for its low DC current readings.  It had the same 0.01 uA resolution as my 34401A and U1252B have and the 0.25, 0.5, 0.75 and 1.0 uA readings were almost identical between the three.  The AN8008 had the same stability for the 0.25 uA reading as the U1252B had.  Both had a little better stability there compared to my 34401A.

I made a quick DC voltage reading comparison between the three and saw 5.00378V from my 34401A, 5.0043 from the U1252B and 5.001 V from the AN8008.  <<< Corrected!

While it is rated to measure the frequency up to 10 MHz I had problems above 5 MHz.  After getting a reading at 6 MHz with a bit larger signal level I stopped trying.  The frequency measurement accuracy was good.  I really liked the 1 mHz resolution below 10 Hz and 10 mHz resolution from there up to just below 100 Hz.  Frequency readings below 1 Hz were difficult to make and only intermittently appeared.  I didn't see much of a sensitivity change between sine and square waves.

Its low value capacitance measurement was limited by just having a nF scale as its lowest with the lack of a zeroing control.

It has passed my tests for good performance from a low cost meter.

I'll probably do a complete accuracy verification test over the weekend but that generally amounts to a lot of numbers which won't reveal much more. 

[deflicted]

... 5.00378V from my 34401A, 5.0043 from the U1252B and 5.001 V from the U1252B.

I'm guessing one of those U1252Bs was supposed to be AN8008? 

[plazma]

Any hacks yet like extra buttons, UART etc.?

In the AN8002 model the UART pin was without bonding wire.

[evava]

And what about swiftness of autoranging (Volts) - for example comparison with UT61e or Fluke 87V or Brymen BM235 ?
On a scale: very slow - slow - moderate - fast - very fast ...

And how long it takes to show value of resistor 1 Ohm, 10 Ohm, 1kOhm, 1MOhm ?
And the same with capacitance.

And REL button can be found on printed board?

[EEVblog]

I just did a 20min review video of the AN8008

[Fungus]

I just did a 20min review video of the AN8008

How come everybody got their meter except me? 

(will your next meter be using this chipset?)

[Muttley Snickers]

I just did a 20min review video of the AN8008

Shorten it to two minutes and post it in the thread linked below, you might be in with a shot, you never know.   

https://www.eevblog.com/forum/contests/giveaway-rohde-schwarz-rtb2004-oscilloscope/