Loading [MathJax]/extensions/Safe.js

Author Topic: Multimeter count  (Read 2834 times)

0 Members and 1 Guest are viewing this topic.

Offline robdejongeTopic starter

  • Regular Contributor
  • *
  • Posts: 84
  • Country: th
Multimeter count
« on: April 02, 2023, 02:57:52 pm »
A decade ago I bought a $5 multimeter to keep around for occasional use like checking a battery voltage or how fast a phone was charging.

A few years ago I bought a 40,000 count multimeter for ~$60. I had started getting into electronics a bit. Low voltage stuff, mostly surrounding home automation and other simple circuits. The occasional more challenging gig. The meter still measures within spec, but I’ve noticed odd behavior. Mechanical issues perhaps.

Now I want to buy a ‘proper’ meter. Something I’m comfortable sticking into mains voltage, something that should be fine for the next 10-20 years. My use case will remain similar, meaning it’s a hobby that I enjoy learning more about. I’ve landed on a Brymen. The question is, do I get a $80, 6,000 count meter that “is fine, I guess” or do I get a $150, 50,000 count meter that is a bit fancier?

I know, I should get what fits my needs.
But what about the 10-20 years lifetime?
And shouldn’t I get the slightly overkill model just for the feel-good factor?
I can afford either. But I also don’t like wasting money.

This is perhaps an odd question, but I thought I’d throw it out there to see what I get back.
 

Offline nightfire

  • Frequent Contributor
  • **
  • Posts: 597
  • Country: de
Re: Multimeter count
« Reply #1 on: April 02, 2023, 04:18:19 pm »
You have 3 parameters to look at here. And to say it first, counts do not necessarily reflect precision of a DMM.

The parameters are:
- build quality and the trust that this device will be still within spec after 10 or 20 years
- basic accuracy
- resolution (=counts displayed)

For the sake of longliving, there are only a handful of manufacturers with a proven track of quality build, where one has a significant number of devices availabe after 20 years.
Fluke is the prime suspect here. Nearly every other brand in the market is whether too young with its current lineup of meters, or the stuff is known as not ultimately longliving...
Keysight essentially bought a company to do handhelds, and seems to retract from that market.
Gossen Metrawatt has a quite fresh overhauled lineup of handhelds, which are nicely build, but the older devices (20+ years) were a company they bought and some models had quite some reputation to go stray with old age.
Brymen: I have heard mixed stuff, here in the forum some cal tech mentioned also something about longterm stability of Brymen DMMs he has seen that came in for check.

Acccuracy: In the specs of the DMM is a table with the accuracy related to each value that can be measured. The question here is: What do you work at, and how precise a DMM has to be?
For electric work and repair stuff, 0.5% basic accuracy in DC and 1.5% in AC is quite sufficient- I myself work on battery charging circuits and decided that I need to be able to have Millivolt precision below 10V, so 0.1% DCV accuracy was asked for.

Resolution: Here are the counts of your DMM. Basically the measured value is broken into the number of counts for display.
Lets say, you have a 6000-count DMM that has a 6V and 60V range, and you measure something with 12V, like a car battery.
This DMM has to use the 60V range, and can measure with a resolution of +/- 10mV display accuracy. (On top of the 0.x% accuracy of the DMM itself)
A 20.000 count DMM usually has a 20V range, and can divide in this range to +/- 1mV

Usually multimeters with higher counts are more expensive and have better basic accuracy due to usage of better parts, but this is not guaranteed- so a look at the specs always is mandated.
You can get some high-quality 6000 count multimeter like Fluke 179 oder 87 with a basic acccuracy of 0.09 or 0.05%, and some 10.000 counts multimeter wit 0.1% or worse basic accuracy.

My approach here would be to define which overall accuracy you really need (at which stuff do you work?) and then define the minimum requirements of the device.
For me, doing some repair work and troubleshooting when repairing broken stuff, a 6000 count DMM would be enough to find the faults. For more precision work, like working on battery chargers etc., I decided on significantly better resolution and accuracy and got some bench DMMs in parallel.
 
 

Offline BeBuLamar

  • Super Contributor
  • ***
  • Posts: 1556
  • Country: us
Re: Multimeter count
« Reply #2 on: April 02, 2023, 04:48:11 pm »
If you think the $150 meter will do you good for 20 years then I think the $90 extra means nothing in 20 years. You do not waste your money. I would be more concerned that the $150 won't be good for you in less than 20 years perhaps 5 years.
 

Offline mwb1100

  • Frequent Contributor
  • **
  • Posts: 710
  • Country: us
Re: Multimeter count
« Reply #3 on: April 02, 2023, 05:16:25 pm »
something that should be fine for the next 10-20 years

I'm not sure if there is a manufacturer that has a reputation for this like Fluke does.  There are countless anecdotes about people who are still using 20 or 30 year old Fluke meters.  Fluke's warranty for their "Industrial product line" is 10 years or 7 years after they discontinue the product - whichever is longer.  (I don't know how the warranty might vary by country. Also, the meter needs to be bought from an authorized dealer to ensure Fluke will honor the warranty.)

On the other hand, you pay for that warranty.  For example, some people consider that if they have to replace a similarly featured Brymen every several years (I think Brymen meters generally have a 1 year warranty), they may come out ahead compared to paying Fluke's price up-front.  So it depends somewhat on if you want to carry a little bit of the risk in order to save some money.

For example, I think the Brymen BM786 is similar in features and build quality to the Fluke 87v. Welectron sells the BM786 for about 150 EUR/160 USD (excluding VAT).  The Fluke 87v (currently out of stock) is priced at about 500 EUR/540 USD (ex VAT). So you could by three BM786 for a bit less than the cost of one 87v.  Don't forget to use the 5% off eevblog code if you buy from welectron.
 

Offline nightfire

  • Frequent Contributor
  • **
  • Posts: 597
  • Country: de
Re: Multimeter count
« Reply #4 on: April 02, 2023, 06:48:32 pm »
Brymen for sure are nice multimeters, and especially when you tinker around with electronics something like the Brymen 786 is reaaally nice to have. But, do you need all of its features?
Doing mains work usually requires less accuracy due to various facts, so unless precision of +/- 1mV is needed for some battery circuits or similar, or the need arises to measure PWM signals/duty cycle, some lesser specc'ed DMM might also do the job.

Seeing the country of the OP, maybe the Fluke 17B+ might be an alternative? Those could be an alternative to the somewhat expensive to models of Fluke, whose features might not be needed.
 

Offline mwb1100

  • Frequent Contributor
  • **
  • Posts: 710
  • Country: us
Re: Multimeter count
« Reply #5 on: April 03, 2023, 07:29:22 am »
the Brymen 786 is reaaally nice to have. But, do you need all of its features?

I used the BM786 in the Fluke comparison because I think it quite comparable to the Fluke 87v (which I chose simply because it's probably the most popular Fluke with more than 6000 counts - maybe the most popular Fluke, period).

I agree that looking at the Asia market Flukes is a good suggestion, but the OP should keep in mind that they have a 1 year warranty.  As far as I can tell from published teardowns, the electronics build on them seems to be similar quality to the "Industrial product line".  I'm not sure if that's the case for the ruggedness (though it may well be).

And if the OP decides not to spring for a high count option like the BM786, the Brymen 235 is a lower cost Brymen option that I think is one of the top values in pro multimeters that might rival the low cost of Asia market Fluke meters.
 

Offline RoGeorge

  • Super Contributor
  • ***
  • Posts: 7222
  • Country: ro
Re: Multimeter count
« Reply #6 on: April 03, 2023, 07:47:23 am »
I have a 100'000 counts mtx3283.  Who cares, 2'000 counts is more than enough for hobby use.

Unless you are into metrology business, the rest is hype with no real use in a hobby lab.  My advice would be to spend the extra budget to buy some other kind of tool/device/instrument you don't have at all, than to buy yet another DMM.

If you insist to have a huge counting range, there are some multimeters based on a 24bits ADC, I remember one called "Mooshimeter".  Seems interesting to not switch ranges at all, but I don't have any 24bits instrument, so no idea how good/bad would this be in practice.

Offline M0HZH

  • Regular Contributor
  • *
  • Posts: 211
  • Country: gb
    • QRPblog
Re: Multimeter count
« Reply #7 on: April 03, 2023, 08:28:33 am »
High counts are only really necessary for really advanced stuff, to see small drift, for design etc. Otherwise you very rarely need to look at more than 4 digits.

There are things that are much more important for hobby / troubleshooting:

- quick start-up time
- good battery life
- reliability (that it won't break down or it won't give false readings)
- good continuity buzzer (very fast, latching)
- good user interface & display
- safety (if you work on mains)
- specific features you might really need.


I'd get the cheaper one and put the rest towards a more useful tool you might need down the line, like a scope.
 

Offline BeBuLamar

  • Super Contributor
  • ***
  • Posts: 1556
  • Country: us
Re: Multimeter count
« Reply #8 on: April 03, 2023, 11:57:33 am »
the Brymen 786 is reaaally nice to have. But, do you need all of its features?

I used the BM786 in the Fluke comparison because I think it quite comparable to the Fluke 87v (which I chose simply because it's probably the most popular Fluke with more than 6000 counts - maybe the most popular Fluke, period).

I agree that looking at the Asia market Flukes is a good suggestion, but the OP should keep in mind that they have a 1 year warranty.  As far as I can tell from published teardowns, the electronics build on them seems to be similar quality to the "Industrial product line".  I'm not sure if that's the case for the ruggedness (though it may well be).

And if the OP decides not to spring for a high count option like the BM786, the Brymen 235 is a lower cost Brymen option that I think is one of the top values in pro multimeters that might rival the low cost of Asia market Fluke meters.
I don't know about the Brymen but the features set of the 87V is quite basic and anything less than that I think the OP will outgrow for sure. I use the 87V daily and I don't think there is a funcion on it that isn't needed.
 
The following users thanked this post: tooki

Offline robdejongeTopic starter

  • Regular Contributor
  • *
  • Posts: 84
  • Country: th
Re: Multimeter count
« Reply #9 on: April 03, 2023, 12:08:08 pm »
If it helps to be more specific:
I’m debating between the BM235 and BM869s
« Last Edit: April 03, 2023, 12:19:53 pm by robdejonge »
 

Offline TAllen

  • Newbie
  • Posts: 1
  • Country: us
Re: Multimeter count
« Reply #10 on: April 03, 2023, 12:12:09 pm »
I've got four 6 multimeters.

Oh.....    I totally misunderstood the subject line.  ::)
« Last Edit: April 03, 2023, 12:13:52 pm by TAllen »
cathodoluminescence - using an electron beam to make rocks light up for petrographic analysis
 
The following users thanked this post: Doctorandus_P, m k

Offline nightfire

  • Frequent Contributor
  • **
  • Posts: 597
  • Country: de
Re: Multimeter count
« Reply #11 on: April 03, 2023, 04:29:35 pm »
If it helps to be more specific:
I’m debating between the BM235 and BM869s
Both are nice multimeters. Given the description of the things you want to do with it, I would suggest the 235, which costs half the price of the 869s, and buy other tools from the money saved.
Like additional testleads or grips, good quality insulated screwdrivers etc., or tools for dismantling cables (cable strippers). Or, given repair use, some of the budget component tester gizmos.
 

Offline rstofer

  • Super Contributor
  • ***
  • Posts: 9985
  • Country: us
Re: Multimeter count
« Reply #12 on: April 03, 2023, 11:25:20 pm »
Any of the Brymen DMMs in the EEVblog Store will be adequate.  I have both the BM235 and 121GW.  I don't know anything about the BM786.

Or you can buy a bunch of Aneng AN8008 -- I like this meter, it is the one I use most often.  Dave did a review and comparison with other DMMs.

https://www.eevblog.com/2018/06/24/eevblog-1095-is-a-38-multimeter-any-good-aneng-q1-review-4k/


You will get more directed replies if you post this kind of thing in the Test Equipment forum here on EEVblog.
« Last Edit: April 03, 2023, 11:27:27 pm by rstofer »
 

Offline Doctorandus_P

  • Super Contributor
  • ***
  • Posts: 4044
  • Country: nl
Re: Multimeter count
« Reply #13 on: April 04, 2023, 09:29:35 am »
6000 count DMM's are a nice "sweet spot". You will have the same resolution as your 40.000 count meter if you want to measure for example common 5V circuits. When I was young, it was not too far after the transition from analog to digital meters. With an analog meter, it's hard to extract more then two significant digits from any range. The then common 2000 count meters were extremely much more accurate. In most practical use cases, an extra digit over the analog meters is useful, but more resolution than that is often not needed. How often did you actually make use of all the digits of your 40.000 count meter?

Another thing to consider is the "s" in the BM869s. It stands for the serial output. Is that useful for you? Brymen is quite spartan in that regard. They use a weird protocol, that sends over the segments of the LCD instead of values, but the protocol is documented. DMM's with Bluetooth are slowly becoming more common.

I dislike the Aneng meters very much. I bought two of them when that craze happened, and they started annoying me right away with constant beeping for no particular reason. One of the first measurements I wanted to do was to check a bunch of new 1k 1% resistors on tolerance. The first resistor I measured was out of tolerance (by about 10%), then I fiddled a bit with the dial knob and the resistor suddenly measured within tolerance. That is simply unacceptable for me.

I would have bought the 121GW if it's software would have been officially open sourced. That way it would be a breeze to for example permanently disable the "auto off" feature. I also like the "weird" extra features of this meter such as 12V LED measurement and SD card logging. But if I'm going to buy a meter in that price range then accuracy and reliability is more important for me and it will be the Brymen meter.

But for "simple" day to day measurements, one of the cheaper Brymens will be just fine. With things like these, I also do not find the price very important. If you spend EUR100 on a decent DMM that is expected to last 20 years, then that is EUR5 per year of use. If you use it a lot, then you may spend more on batteries.

For electronics, it's also nice to have more then one meter, so you can for example measure voltage and current at the same time, or have one meter continuously monitor some value while you use the other meter to poke around in your circuit.
 
The following users thanked this post: mwb1100


Share me

Digg  Facebook  SlashDot  Delicious  Technorati  Twitter  Google  Yahoo
Smf