Author Topic: What's the cheapest 0.02% accuracy handheld meter  (Read 9290 times)

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Offline CosteC

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Re: What's the cheapest 0.02% accuracy handheld meter
« Reply #50 on: July 14, 2023, 04:30:20 pm »
CosteC made a good point but just didn't choose the best example to illustrate the issue. 
You are welcome :) Lets examine something better than ANENG. Or at least seemingly better.
The 869S is a "0.02%" meter,
It is 0.02% meter, Brymen style: at two ranges 0.2%, worse for other 3 ranges: 0.3%, 0.4% and 0.15% for 500-1000 VDC.

BM869S has 0.3% +20d on 500.00 mV range. For case mentioned this means 0.5 mV error - 0.5%. Surprisingly it is BEST AC range. 500 VAC range has 0.5% + 40d. At best 45-300 Hz case.

Brymen is 0.1% better than Aneng AN870 in this scenario (quite realistic as sub 1 V AC measurements are not so rare)
 

Offline bdunham7

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Re: What's the cheapest 0.02% accuracy handheld meter
« Reply #51 on: July 14, 2023, 04:44:37 pm »
You can probably find some random spec where 0.03% Brymen is better than that 289. Does that mean anything? No.

Choosing the meter based on the headline spec doesn't tell you which one is more accurate for a specific case.  And if that doesn't mean anything, then what's the point of the whole discussion?
A 3.5 digit 4.5 digit 5 digit 5.5 digit 6.5 digit 7.5 digit DMM is good enough for most people.
 
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Online Aldo22

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Re: What's the cheapest 0.02% accuracy handheld meter
« Reply #52 on: July 14, 2023, 05:10:40 pm »
If you work in a restaurant kitchen from freezer to pizza oven, you better use an AN8008.
It gives more stable readings over the temperature range than a BM869s says joe smith.
https://youtu.be/TSGLA9heboY?t=1768

 :-DD
 

Offline alm

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Re: What's the cheapest 0.02% accuracy handheld meter
« Reply #53 on: July 14, 2023, 10:02:23 pm »
I disagree here, It's just cherry picking points for distraction. 400A is definitely not common. You can probably find some random spec where 0.03% Brymen is better than that 289. Does that mean anything? No.
If you need the meter for a particular task, like adjusting a trimmer so the voltage between two test points reads 9 V  +/- 0.05% with 99% confidence, then yes, it makes a difference if a meter is +/- 0.02% or +/- 0.07% in that range. But another person might me measuring 900V all day. This means the question which of the meters offers the best accuracy might have a different answer for those two people.

Offline miegapeleTopic starter

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Re: What's the cheapest 0.02% accuracy handheld meter
« Reply #54 on: July 15, 2023, 04:41:41 am »
I disagree here, It's just cherry picking points for distraction. 400A is definitely not common. You can probably find some random spec where 0.03% Brymen is better than that 289. Does that mean anything? No.
If you need the meter for a particular task, like adjusting a trimmer so the voltage between two test points reads 9 V  +/- 0.05% with 99% confidence, then yes, it makes a difference if a meter is +/- 0.02% or +/- 0.07% in that range. But another person might me measuring 900V all day. This means the question which of the meters offers the best accuracy might have a different answer for those two people.

Yes, but that's precisely what's cherry picking and distracting is. You can quote millions different scenarios, and some meters will be better suited than others, but I wrote what I need, and that is "cheapest 0.02%" multimeter, so I can sleep calm knowing my AA battery is 1.456V and not some lousy 1.455V. I thought maybe I missed something cheap, but unfortunately such thing does not exist. I guess market is too small  :)
Obviously it's SOP in here for some to bring FLUKEs every time, although topic clearly states "cheapest", but I guess that's nice for entertainment .
 

Offline bdunham7

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Re: What's the cheapest 0.02% accuracy handheld meter
« Reply #55 on: July 15, 2023, 05:06:54 am »
but I wrote what I need, and that is "cheapest 0.02%" multimeter, so I can sleep calm knowing my AA battery is 1.456V and not some lousy 1.455V. I thought maybe I missed something cheap, but unfortunately such thing does not exist

OK, the 10,000 count Fairchild 7000A is specified for 0.01% + 1 count.  I got mine for $100, although you might struggle to find the same deal these days.  And it needed a bit of work too.
A 3.5 digit 4.5 digit 5 digit 5.5 digit 6.5 digit 7.5 digit DMM is good enough for most people.
 

Offline miegapeleTopic starter

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Re: What's the cheapest 0.02% accuracy handheld meter
« Reply #56 on: July 15, 2023, 07:31:52 am »
OK, the 10,000 count Fairchild 7000A is specified for 0.01% + 1 count.  I got mine for $100, although you might struggle to find the same deal these days.  And it needed a bit of work too.
Thank you, that's actually way more relevant than all these "but what if you want to measure primary current of nuclear power station transformer" comments.
 

Offline mwb1100

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Re: What's the cheapest 0.02% accuracy handheld meter
« Reply #57 on: July 15, 2023, 02:50:21 pm »
so I can sleep calm knowing my AA battery is 1.456V and not some lousy 1.455V

Oh my God - there's someone else with that problem?
 

Offline bdunham7

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Re: What's the cheapest 0.02% accuracy handheld meter
« Reply #58 on: July 15, 2023, 04:14:07 pm »
so I can sleep calm knowing my AA battery is 1.456V and not some lousy 1.455V

Oh my God - there's someone else with that problem?

I would refer you both to this thread:

https://www.eevblog.com/forum/beginners/battery-voltage-reduces-the-longer-it-is-being-mm-voltage-tested/msg4930432/#msg4930432

 :-DD
A 3.5 digit 4.5 digit 5 digit 5.5 digit 6.5 digit 7.5 digit DMM is good enough for most people.
 
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Offline miegapeleTopic starter

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Re: What's the cheapest 0.02% accuracy handheld meter
« Reply #59 on: July 15, 2023, 08:17:23 pm »
With 10M input resistance and 4 digits you need to wait quite a long time to see a drop. But with 6 or 7 digit DMM it's quite easily visible. Dave showed it in one of his videos.
 

Offline Fungus

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Re: What's the cheapest 0.02% accuracy handheld meter
« Reply #60 on: July 16, 2023, 02:47:22 am »
With 10M input resistance and 4 digits you need to wait quite a long time to see a drop. But with 6 or 7 digit DMM it's quite easily visible. Dave showed it in one of his videos.

A handheld with a 500,000 count mode shows it quite well...  :)
 

Offline bdunham7

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Re: What's the cheapest 0.02% accuracy handheld meter
« Reply #61 on: July 16, 2023, 03:42:27 am »
A handheld with a 500,000 count mode shows it quite well...  :)

I've lost the plot--what is "it"?
A 3.5 digit 4.5 digit 5 digit 5.5 digit 6.5 digit 7.5 digit DMM is good enough for most people.
 

Offline Veteran68

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Re: What's the cheapest 0.02% accuracy handheld meter
« Reply #62 on: July 16, 2023, 03:44:21 am »
A handheld with a 500,000 count mode shows it quite well...  :)

I've lost the plot--what is "it"?

Sounds like they're talking about watching a battery's voltage being drained by the measuring meter.
 
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Offline bdunham7

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Re: What's the cheapest 0.02% accuracy handheld meter
« Reply #63 on: July 16, 2023, 04:30:32 am »
Sounds like they're talking about watching a battery's voltage being drained by the measuring meter.

Hmmm, do you mean like this?   :)

https://youtu.be/g8wDRsnLrEc

A 3.5 digit 4.5 digit 5 digit 5.5 digit 6.5 digit 7.5 digit DMM is good enough for most people.
 
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Offline Fungus

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Re: What's the cheapest 0.02% accuracy handheld meter
« Reply #64 on: July 16, 2023, 05:12:04 am »
Sounds like they're talking about watching a battery's voltage being drained by the measuring meter.

Hmmm, do you mean like this?   :)

https://youtu.be/g8wDRsnLrEc

Nope. definitely not like that. That guy's fingers are probably draining the battery faster than the meter.
 

Offline bdunham7

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Re: What's the cheapest 0.02% accuracy handheld meter
« Reply #65 on: July 16, 2023, 05:15:14 am »
Nope. definitely not like that. That guy's fingers are probably draining the battery faster than the meter.

I have really dry hands so that generally isn't a problem.  Not that it matters in this case--look more closely at the numbers. 
A 3.5 digit 4.5 digit 5 digit 5.5 digit 6.5 digit 7.5 digit DMM is good enough for most people.
 

Offline Fungus

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Re: What's the cheapest 0.02% accuracy handheld meter
« Reply #66 on: July 16, 2023, 05:23:52 am »
Nope. definitely not like that. That guy's fingers are probably draining the battery faster than the meter.

I have really dry hands so that generally isn't a problem.  Not that it matters in this case--look more closely at the numbers.

Your hand is conducting electricity and warming up the battery?  :-//
 

Offline bdunham7

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Re: What's the cheapest 0.02% accuracy handheld meter
« Reply #67 on: July 16, 2023, 05:43:26 am »
Your hand is conducting electricity and warming up the battery?  :-//

No, neither really.  Just to be sure I measured my fingers in the same positions I was holding the battery and with the same probes.  With approximately the same pressure used to hold the battery, I'm 106M.  With a lot more pressure, 26M.  And the battery was cooling down, it had been in a warmer spot.

The whole theme of this thread (to me) is making assumptions without examining them and even resisting challenges to them.  The original example was "I want a more accurate (cheap) multimeter and I'm going to judge that solely by the advertised basic DC accuracy headline spec".  Now we have drifting battery voltages and assumptions about why that happens.

You see a battery connected to a many-digit multimeter with the LSD slowly counting down.  You assume that the reason for that is that the ~150nA is flowing in a 1.5V/10M circuit is drawing down the battery.  You see someone doing the same thing but holding the battery in their hand and the voltage is going up, you assume the reason is that the battery temperature is increasing.  It turns out that there might be other reasons for these behaviors and unless you somehow quantify the effects that you attribute the changes to, you can't reliably assign causes to your observations.

With an AA battery, unless you can accurately (very accurately) measure temperature and also know how the battery behaves, thermal effects will probably outweigh all those other things by quite a bit.  In this case, at near room temperatures, the battery voltage goes down as the battery warms up and there is no discernable difference between the 10M and Hi-Z modes on the meter.  If I hold the battery differently so as not to 'short' it with my 100M fingers the voltage changes (drops)  more quickly, presumably because more of my hand is in contact with it and thus it warms faster.  This is not what I expected when I tried this out just a bit ago.

Things are never as simple as we want them to be.
A 3.5 digit 4.5 digit 5 digit 5.5 digit 6.5 digit 7.5 digit DMM is good enough for most people.
 

Offline mwb1100

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Re: What's the cheapest 0.02% accuracy handheld meter
« Reply #68 on: July 16, 2023, 07:19:46 am »
Speaking for myself, my comment was just a joke about obsessing over a AA battery measuring 1.456V vs 1.455V. Ie., that I sometimes obsess over absurd things.
 

Offline Fungus

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Re: What's the cheapest 0.02% accuracy handheld meter
« Reply #69 on: July 16, 2023, 07:31:27 am »
Speaking for myself, my comment was just a joke about obsessing over a AA battery measuring 1.456V vs 1.455V. Ie., that I sometimes obsess over absurd things.

We know :-)
 

Online Aldo22

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Re: What's the cheapest 0.02% accuracy handheld meter
« Reply #70 on: July 16, 2023, 08:20:23 am »
My cheapest DMM has a battery test mode.
Isn't it better anyway to measure the batteries under load?

Quote
Battery test:
50mA load current in 1.5V range
5mA load current in 9V range
 

Offline miegapeleTopic starter

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Re: What's the cheapest 0.02% accuracy handheld meter
« Reply #71 on: July 16, 2023, 09:29:12 am »
Hmmm, do you mean like this?   :)

https://youtu.be/g8wDRsnLrEc
unlisted? You should be posting this to TikTok with some free energy clickbait title  ;D
 

Offline Fungus

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Re: What's the cheapest 0.02% accuracy handheld meter
« Reply #72 on: July 16, 2023, 10:54:33 am »
unlisted? You should be posting this to TikTok with some free energy clickbait title  ;D

Electroman charging up a battery with his fingers.
 

Offline BeBuLamar

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Re: What's the cheapest 0.02% accuracy handheld meter
« Reply #73 on: July 16, 2023, 01:46:00 pm »
Speaking for myself, my comment was just a joke about obsessing over a AA battery measuring 1.456V vs 1.455V. Ie., that I sometimes obsess over absurd things.

But if I measure an AA battery with no load and it reads either 1.456 or 1.455V I would toss it.
 

Offline Fungus

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Re: What's the cheapest 0.02% accuracy handheld meter
« Reply #74 on: July 16, 2023, 02:40:51 pm »
But if I measure an AA battery with no load and it reads either 1.456 or 1.455V I would toss it.

I draw the line at 1.450 myself
 


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