Author Topic: Another cheapo multimeter: 19999 count, 0.05% DC accuracy  (Read 50845 times)

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Offline nidlaXTopic starter

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Another cheapo multimeter: 19999 count, 0.05% DC accuracy
« on: March 05, 2018, 11:09:48 am »
Also known as the AN870 or the Richmeters RM219.

AN870 eBay example: https://www.ebay.com/itm/AN870-Digital-Voltmeter-Ammeter-Ohmmeter-Multimeter-Volt-AC-DC-Tester-Meter-MT/352297173058

RM219: https://www.aliexpress.com/item/RM219-True-RMS-19999-Counts-Digital-Multimeter-NCV-Frequency-Auto-Power-off-AC-DC-Voltage-Ammeter/32850861443.html

Anyone have hands-on experience with these? Not quite as cheap as the HY-19E / Surpeer on Amazon right now.
« Last Edit: March 05, 2018, 11:14:41 am by nidlaX »
 

Offline Mark Hennessy

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Re: Another cheapo multimeter: 19999 count, 0.05% DC accuracy
« Reply #1 on: March 05, 2018, 11:45:36 am »
My first reaction was "Ah - it's finally been spotted in the wild!" - see the ante-penultimate paragraph of this post:

https://www.eevblog.com/forum/beginners/opinion-on-a-bside-zt302-multimeter/msg1344853/#msg1344853

But the more I look, it seems like a 19,999-count version of the AN860B, rather than a 19,999-count version of the ZT301. It appears to have a separate holster (good), but if it's the same size as the AN860B, that's quite a large meter, as my pictures show - practically Fluke 87V size. Personally, I quite like the small size of the ZT301.

I see it's available on eBay UK for £27 - thanks for the pointer :-+

Meanwhile, has anyone seen the 19,999-count of the ZT301 yet? The BSIDE website is of little help, needless to say.
 

Offline Fungus

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Re: Another cheapo multimeter: 19999 count, 0.05% DC accuracy
« Reply #2 on: March 05, 2018, 03:21:20 pm »
This one is interesting, too:

https://www.eevblog.com/forum/testgear/surpeer-av4-true-rms-4-5-digit-multimeter/

It's about the same price/accuracy but it has dual display, bar graph, etc.
« Last Edit: March 05, 2018, 03:41:43 pm by Fungus »
 

Offline Gandalf_Sr

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Re: Another cheapo multimeter: 19999 count, 0.05% DC accuracy
« Reply #3 on: March 05, 2018, 04:13:32 pm »
A just ordered an AN870 from eBay for $37.
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Online Kleinstein

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Re: Another cheapo multimeter: 19999 count, 0.05% DC accuracy
« Reply #4 on: March 05, 2018, 05:01:50 pm »
Probably the difference between resolution and accuracy got somewhat lost in translation. 4.5 digits provide 0.05% of resolution, but accuracy is usually lower in cheap meters - more like 1% or maybe 0.5%.
 

Offline precaud

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Re: Another cheapo multimeter: 19999 count, 0.05% DC accuracy
« Reply #5 on: March 06, 2018, 04:43:53 am »
No mention of bandwidth in ACV... or ACI... deal-breaker if its the same 3kHz as its siblings.\
It's the same size as the AN860B+.
« Last Edit: March 06, 2018, 04:50:20 am by precaud »
 
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Offline BradC

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Re: Another cheapo multimeter: 19999 count, 0.05% DC accuracy
« Reply #6 on: March 06, 2018, 04:55:19 am »
Hrm. 20A range. Finally something that might replace my ageing Protek 506. Might have to have a closer look at this one.

Specs would indicate it's an order of magnitude more accurate on DCV, twice as accurate on DCA, 3 times as accurate on ACV, about the same on resistance and a tenth as accurate on frequency.

I wonder how close it actually gets to its accuracy specs?
 

Online egonotto

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Re: Another cheapo multimeter: 19999 count, 0.05% DC accuracy
« Reply #7 on: March 06, 2018, 05:51:25 am »
Hello,

0.05% from 19999 is 9.9995

Best regards
egonotto
 

Offline BroMarduk

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Re: Another cheapo multimeter: 19999 count, 0.05% DC accuracy
« Reply #8 on: March 07, 2018, 07:51:08 pm »
Seems similar to the HY-19E (https://www.banggood.com/HY-19E-20000-Counts-NCV-Multimeter-AC-DC-Voltage-Current-Resistances-Capacitors-Diodes-Temp-Tester-p-1153062.html?rmmds=search&cur_warehouse=CN) with different button placements (same rotory positions).

HY-19E also has a dual LCD (for Hz with AC V/mV) and bar graph (albeit with the same refresh rate as the display).   

More accurate than any of the Anengs I have, but I don't have this new Aneng/Richmeter.
 

Offline maginnovision

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Re: Another cheapo multimeter: 19999 count, 0.05% DC accuracy
« Reply #9 on: March 07, 2018, 10:00:16 pm »
For some reason I bought 2. I'll check them out when they show up.
 

Offline casinada

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Re: Another cheapo multimeter: 19999 count, 0.05% DC accuracy
« Reply #10 on: March 07, 2018, 10:23:15 pm »
https://www.ebay.com/itm/20000counts-Multimeter-Digital-LCD-Professional-Voltmeter-Current-Tester-RMS/372140030906?ssPageName=STRK%3AMEBIDX%3AIT&_trksid=p2057872.m2749.l2649

I purchased it in December. There is no way to change the contrast that is not good at certain angles.
I paid $28.84 shipped but comes without pouch  :-//
 

Online thm_w

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Re: Another cheapo multimeter: 19999 count, 0.05% DC accuracy
« Reply #11 on: March 07, 2018, 10:40:09 pm »
Hrm. 20A range. Finally something that might replace my ageing Protek 506. Might have to have a closer look at this one.

Specs would indicate it's an order of magnitude more accurate on DCV, twice as accurate on DCA, 3 times as accurate on ACV, about the same on resistance and a tenth as accurate on frequency.

I wonder how close it actually gets to its accuracy specs?

The 506 is rated for 20A. Keep in mind that on almost all meters the 20A spec is only for a short time (10-20A for 30s max).
You can also cal the 506 yourself if you have a good reference meter. Its probably typically a bit better than 0.5% on DCV.

But anyway, this is a $40 meter, some things will be better, certainly some things will be worse as well. Would be impressed if it hits that 0.005%.
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Offline Fungus

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Re: Another cheapo multimeter: 19999 count, 0.05% DC accuracy
« Reply #12 on: March 07, 2018, 11:36:50 pm »
For some reason I bought 2. I'll check them out when they show up.

2 of which one?
 

Offline maginnovision

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Re: Another cheapo multimeter: 19999 count, 0.05% DC accuracy
« Reply #13 on: March 08, 2018, 02:32:01 am »
For some reason I bought 2. I'll check them out when they show up.

2 of which one?

The aneng an870.
 
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Offline maginnovision

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Re: Another cheapo multimeter: 19999 count, 0.05% DC accuracy
« Reply #14 on: March 20, 2018, 04:27:26 am »
I don't know if anyone is interested but my two ANENG AN870 showed up today. Turned them on and both had batteries at about 80C after a few seconds. One because a switch contact was bad. The other... I'm still working on. There is a single PTC on V input, and what looks to be a TVS on the ma/ua input. The SMD soldering is ok, and the through-hole isn't. It's too thin and instills little confidence that the leads are making good contact with the sleeves. The holster is super cheap and the range switch really stiff. Display seems fine and the case feels solid. The buttons are a bit squishy but ok. I'll update more on how close it reads to keysight 1252 once I get the second one working.
 

Offline Fungus

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Re: Another cheapo multimeter: 19999 count, 0.05% DC accuracy
« Reply #15 on: March 20, 2018, 05:20:16 am »
I don't know if anyone is interested but my two ANENG AN870 showed up today. Turned them on and both had batteries at about 80C after a few seconds. One because a switch contact was bad. The other... I'm still working on. There is a single PTC on V input, and what looks to be a TVS on the ma/ua input. The SMD soldering is ok, and the through-hole isn't. It's too thin and instills little confidence that the leads are making good contact with the sleeves. The holster is super cheap and the range switch really stiff. Display seems fine and the case feels solid. The buttons are a bit squishy but ok. I'll update more on how close it reads to keysight 1252 once I get the second one working.
Please keep us informed.

I'm also interested in how fast the readings settle, etc.
 

Offline maginnovision

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Re: Another cheapo multimeter: 19999 count, 0.05% DC accuracy
« Reply #16 on: March 20, 2018, 07:16:37 am »
Well some quick tests... I set up power supply to run through 3 voltages. They were 1.263V, 17.632V, and 23.928V.
The keysight read 1.2624V, 17.630V, and 23.928V. The 870 read 1.2623V, 17.633V, and 23.93V.
So that seems alright. I also set it to switch between them every second. The keysight I could see the voltages every time. The 870 I could see 17, and 23 but it never had time to range for 1V.

A 0.68 ohm resistor read .69/.70 on keysight and 0.73 on 870.
A 2.2 ohm resistor read 2.22 on keysight and read 2.27 on 870.
No rel to account for leads but for everything I used the same leads just swapping input jacks so apples to apples. The resistance kept going down on the 870 but I stopped at 5 seconds because that's about the maximum patience I'd usually have. The keysight was a second or less to stable. Both resistors were 5W 1% tolerance and 50ppm stability.

47nF capacitor: Keysight was 48.30nF, 870 was 46.10nF. 47uF: Keysight was 49.21uF, 870 was 49.22uF and pretty slow to figure it out. The capacitors were 50V 10% tolerance.

So it seems alright in accuracy but definitely slower than the keysight, surprise. The real problems for me are that 1 of 2 arrived with what appears to be a short under the blob over die(This could have been from sticking it in a mains outlet just to see if it'd blow up, but it didn't seem to have a problem reading it). The leads are not very good and don't seem to make good contact, the extra leads it came with would be better but then you've got longer leads and screw connections at both ends. The multimeter specific leads in general were probably trash. I couldn't even verify they used pvc for the insulator because they said nothing. I think the manual warnings of 36vdc and 24vac as limits is a good indication not to mess around and at least get some decent leads (and avoid mains).
« Last Edit: March 20, 2018, 07:51:20 am by maginnovision »
 
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Offline precaud

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Re: Another cheapo multimeter: 19999 count, 0.05% DC accuracy
« Reply #17 on: March 20, 2018, 01:19:07 pm »
A 0.68 ohm resistor read .69/.70 on keysight and 0.73 on 870.
A 2.2 ohm resistor read 2.22 on keysight and read 2.27 on 870.
No rel to account for leads but for everything I used the same leads just swapping input jacks so apples to apples.

Not a fair test. You need to use Rel when measuring low-value resistors with 2-wire Ohms.

Quote
The resistance kept going down on the 870 but I stopped at 5 seconds because that's about the maximum patience I'd usually have. The keysight was a second or less to stable. Both resistors were 5W 1% tolerance and 50ppm stability.

That is a genuine concern. Either variable contact resistance, or too-low current for low-value Ohms to begin with. Might be worth examining solder connections of the input jacks to the pcb. And fuse holders.
 

Offline dave356

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Re: Another cheapo multimeter: 19999 count, 0.05% DC accuracy
« Reply #18 on: March 20, 2018, 02:49:09 pm »
Looks like the voltage rail is the same as the aneng 8008.

1-100uf cap on rail with space for extra smd caps, just like 8008.
 
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Offline maginnovision

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Re: Another cheapo multimeter: 19999 count, 0.05% DC accuracy
« Reply #19 on: March 20, 2018, 02:52:23 pm »
It may not seem fair but again it was the same resistors, same leads, and they weren't repositioned on the resistors. The soldering wasn't very well done but I got similar results before and after touching up the through hole soldering. It would make sense that it has too low drive current since the 47uF capacitor also took a while to get a reading. If it weren't 1am I would have tried more things, like AC readings, which I may do tonight if I have a chance. If I do I'll see if I can get it to stabilize for relative measurement but it was being fickle so I didn't bother for either meter.
 

Offline JohnPen

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Re: Another cheapo multimeter: 19999 count, 0.05% DC accuracy
« Reply #20 on: March 20, 2018, 03:03:33 pm »
I notice the switch side PCB picture refer's to 10A not 20A maybe its only 15 secs. ;D
 

Offline Fungus

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Re: Another cheapo multimeter: 19999 count, 0.05% DC accuracy
« Reply #21 on: March 20, 2018, 06:43:00 pm »
It may not seem fair but again it was the same resistors, same leads, and they weren't repositioned on the resistors. The soldering wasn't very well done but I got similar results before and after touching up the through hole soldering. It would make sense that it has too low drive current since the 47uF capacitor also took a while to get a reading. If it weren't 1am I would have tried more things, like AC readings, which I may do tonight if I have a chance. If I do I'll see if I can get it to stabilize for relative measurement but it was being fickle so I didn't bother for either meter.

Put another meter in series and watch the current.  :popcorn:
 

Offline maginnovision

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Re: Another cheapo multimeter: 19999 count, 0.05% DC accuracy
« Reply #22 on: March 21, 2018, 05:00:58 am »
Capacitance looks like it starts at 19.81uA and tops out at 388.85uA at OL. Ohms looks about 387.02uA and diode mode about 1.781mA(1692.3uA in uA range)(3.3V of course).

The frequency counter looks good up to 19.99MHz with a sine wave at 2.5Vpp. 1.61Vpp was the lowest it was still reading correctly, 1.58Vpp for 10MHz(9.999MHz reading). 117mVpp was about where it stopped reading a 5MHz(4.999MHz reading) sine wave and 1Hz was as low as it would go.

2.426mA for a small pierce-gate oscillator on 870, 2.437mA shown on keysight. 14.528mA for a 3V3/1V0 dual buck converter supply board with no load on 870, 14.616mA on keysight. 0.8724A for dual 3W leds driven from a 5V0 -> 3V3 dual buck converter on 870, 0.8757A for keysight. For reference power supply read 0.878A, but it reads 3mA with no load.

60Hz 500mVpp read 0.3533V on 870, read 0.3535V on keysight. 60Hz 2.5Vpp read 1.7635V on 870, read 1.7601V on keysight.

The AC voltages and the frequencies were generated by built in function generator on R&S RTB2004 so there is bound to be some error at generation too. All in all it seems pretty decent used in a low voltage space. If anyone wants to know anything else I'm happy to test what I'm able to.
« Last Edit: March 21, 2018, 05:11:38 am by maginnovision »
 

Offline precaud

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Re: Another cheapo multimeter: 19999 count, 0.05% DC accuracy
« Reply #23 on: March 21, 2018, 09:29:16 am »
What's the -3dB BW for ACV from say 1Vpp?
Does it use AA or AAA batteries?
 

Offline Gandalf_Sr

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Re: Another cheapo multimeter: 19999 count, 0.05% DC accuracy
« Reply #24 on: March 21, 2018, 11:12:13 am »
Mine arrived yesterday, took it out of the packet and fitted 2 x AA batteries - it turns on and I see stuff on the display which is nice and clear (and BIG - good for my old eyes).  I'll do some more tests and report back. Let me know if you want something specific tested - I have a calibrated 6.5 digit Keysight for comparison - LOL, a $22 (shipped) meter Vs a $1,000 meter!
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