Author Topic: Help buying my first digital multimeter  (Read 19341 times)

0 Members and 1 Guest are viewing this topic.

Offline SepehrTopic starter

  • Contributor
  • Posts: 20
  • Country: ir
Help buying my first digital multimeter
« on: May 09, 2017, 06:43:49 pm »
Hello, World!
I'm an EE student (freshman) and I love electronics, so I'm going to buy my first DMM mostly for my electronics projects plus for repairing some household devices. Now, the problem is that I can't easily purchase top quality DMMs like high-end Fluke models or Gossen Metrawatt, etc. They are either overpriced or not easily found on the market (especially Gossen Metrawatt is rarely found). Unfortunately, I can't [easily] buy from eBay or other international online shopping websites not based in Iran, and even if I could, there would be lots of problems with shipping to Iran or currency exchanges, etc. So I have to stick to local market anyways.

After watching Dave's Digital Multimeter Buying Guide (EEVblog #75), I think that I need the following specifications for my DMM to best fit my needs for electronics. Please correct me if I'm wrong.

• It should have Autoranging feature and it'd be nice to have the feature of selecting between Manual and Autoranging
• It should have an AC or DC volts range of 200mV up to say, 1000V (NOT those designed for electricians)
• Ohms range of 200? up to 20M?
• Microamps and/or Milliamps
• Input impedance of at least 10M?
• Separate terminals like (A-mA ?A-COM-V?) not (V?mA)
• HRC fuses not glass fuses
• Maximum test voltage of 4V for diode test
• A decent continuity test function (not delayed or scratched tone)
• A reasonable and acceptable battery life
• Capacitor test function would be nice (pF and nF)
• REL function (Relative Measurement)
• Hold or Autohold function ± MIN MAX function
• Basic DC volts accuracy of at least 0.5%
• High display updating and autoranging speed
• Burden voltage 1mV/mA or 0.1 mV/?A
+ other basic essentials

It's easy to find Chinese DMMs with fewer prices like UNI-T, Victor, etc but I'm not sure which model should I buy. I found Fluke 15B, 17B, 106 and 101 amongst relatively affordable Fluke DMMs but I've heard somewhere that Fluke 15B and 17B are not as good as their brand suggests, so maybe they don't worth their price.

Also Hioki ones, like DT-4211 or higher models.

Any recommendations or advice would be much much appreciated!  :clap:

EDIT: It looks like that the editor replaced my ohms and micro symbols with question marks... I'll fix it as soon as possible.
« Last Edit: May 09, 2017, 06:46:12 pm by Sepehr »
Quote
There is as yet insufficient data for a meaningful answer."
Isaac Asimov
 

Offline rstofer

  • Super Contributor
  • ***
  • Posts: 9890
  • Country: us
Re: Help buying my first digital multimeter
« Reply #1 on: May 09, 2017, 07:28:12 pm »
There are UNI-T models that are quite popular.  Look over in the Test Equipment forum and use the Search feature.
There is also a 'sticky' spreadsheet of DMMs at the top of the forum and a 'sticky' thread re: DMMs that probably don't meet the safety specs.
 

Offline Lightages

  • Supporter
  • ****
  • Posts: 4314
  • Country: ca
  • Canadian po
Re: Help buying my first digital multimeter
« Reply #2 on: May 09, 2017, 08:33:07 pm »
You are asking for quite a bit. Do some research using the most excellent work done by Wytnucls here:
https://www.eevblog.com/forum/testgear/multimeter-spreadsheet/

You can look for all the specifications you want. This is probably the most comprehensive method for you to find what you are looking for.

If you must buy a Uni-T you won't find everything you want but consider the UT-139C or the UT-171B.
 

Offline shteii01

  • Frequent Contributor
  • **
  • Posts: 266
  • Country: us
Re: Help buying my first digital multimeter
« Reply #3 on: May 10, 2017, 01:01:27 am »
Just to be a smart a$$ I will say: Fluke 87 Series 5.
 

Offline P90

  • Frequent Contributor
  • **
  • Posts: 640
Re: Help buying my first digital multimeter
« Reply #4 on: May 10, 2017, 01:53:24 am »
...
« Last Edit: May 10, 2017, 02:40:16 am by P90 »
 

Offline SepehrTopic starter

  • Contributor
  • Posts: 20
  • Country: ir
Re: Help buying my first digital multimeter
« Reply #5 on: May 10, 2017, 01:17:18 pm »
Thanks, everyone. I had looked that spreadsheet, but it lacks some models that I can buy locally.
I'd like to know your comments on HIOKI DT-4211 as it's the only non-Chinese brand that I can buy although there are Fluke 101 and 106 and 15B which are made in China and some people claim that the 15B model is not very accurate and it has low autoranging and updating speed. Fluke 101 and 106 have much fewer functions on them compared to HIOKI DT-4211.
« Last Edit: May 10, 2017, 01:19:31 pm by Sepehr »
Quote
There is as yet insufficient data for a meaningful answer."
Isaac Asimov
 

Offline P90

  • Frequent Contributor
  • **
  • Posts: 640
Re: Help buying my first digital multimeter
« Reply #6 on: May 10, 2017, 01:48:11 pm »
the Hioki has very low specs, nothing special for the price, and I think 3 updates a second, again, nothing special. I'd take the uni-t 139-c over those choices you listed...
 

Online David Hess

  • Super Contributor
  • ***
  • Posts: 16614
  • Country: us
  • DavidH
Re: Help buying my first digital multimeter
« Reply #7 on: May 10, 2017, 01:49:44 pm »
It should have Autoranging feature and it'd be nice to have the feature of selecting between Manual and Autoranging

Autoranging used to be a premium feature but I think today it is just a way to make a less expensive meter.  And with autoranging, manual ranging is more complicated and takes more time.  The difference is insignificant.

Quote
Input impedance of at least 10M?

I would avoid any meter which is not 10M on every AC and DC voltage range unless it is only going to be used in low impedance and low precision applications like power supplies.  Some cheap meters are 9M or 11M on just some (!) DC ranges and 1M on AC ranges which leads to inconsistent voltage measurements.

Quote
Separate terminals like (A-mA ?A-COM-V?) not (V?mA)

Hopefully nobody is making a meter with voltage and amps on the same terminal.  I have a couple of old bench meters like this and one has to be careful not to short out a voltage source when changing modes.

I really like the old Beckman RMS225 design where all three terminals, milliamps, amps, and volts-ohms, had the same spacing to the common terminal so standard 3/4 inch banana jacks could be used but these days only B&K and Amprobe/Wavetek/Meterman (they inherited Beckman's design) make meters like this.

Quote
Capacitor test function would be nice (pF and nF)

This is almost always useless; I never know when to trust it and it only works correctly for trivial cases.  Get a dedicated LCR meter like a DE-5000 or impedance bridge (if you can stand using it) if testing capacitors is important.

Quote
Hold or Autohold function ± MIN MAX function

Some meters have a really slow minimum/maximum function.  Do not count on this to capture power line voltage spikes.

Quote
other basic essentials

One of my old Beckman meters had a bipolar transistor hfe test function which I miss.  This is not as useful as it used to be unless you are still using leaded parts.

Temperature measurement using standard type K thermocouples is nice to have.  This is better if a dedicated thermocouple socket is used instead of an adapter but either are acceptable until the adapter is lost.

One of my high end meters supports separate average, RMS, *and* RMS AC+DC measurements which is very handy for doing calibration.

Wide bandwidth AC and RMS AC measurements are needed sometimes; better meters top out at 100kHz but I would not mind finding one which went higher.

You might not be able to get everything you want in a single meter and it may not even be preferable.  Consider an inexpensive meter which has more special functions and a more expensive meter that is higher performance.  Maybe buy the inexpensive meter first to get some experience so you know better what you want.
« Last Edit: May 10, 2017, 01:51:39 pm by David Hess »
 
The following users thanked this post: Electro Detective

Offline SepehrTopic starter

  • Contributor
  • Posts: 20
  • Country: ir
Re: Help buying my first digital multimeter
« Reply #8 on: May 10, 2017, 03:34:47 pm »
the Hioki has very low specs, nothing special for the price, and I think 3 updates a second, again, nothing special. I'd take the uni-t 139-c over those choices you listed...
Which specs do you consider low?
What about SANWA CD771 and HIOKI DT4253?
It should have Autoranging feature and it'd be nice to have the feature of selecting between Manual and Autoranging

Autoranging used to be a premium feature but I think today it is just a way to make a less expensive meter.  And with autoranging, manual ranging is more complicated and takes more time.  The difference is insignificant.

Quote
Input impedance of at least 10M?

I would avoid any meter which is not 10M on every AC and DC voltage range unless it is only going to be used in low impedance and low precision applications like power supplies.  Some cheap meters are 9M or 11M on just some (!) DC ranges and 1M on AC ranges which leads to inconsistent voltage measurements.

Quote
Separate terminals like (A-mA ?A-COM-V?) not (V?mA)

Hopefully nobody is making a meter with voltage and amps on the same terminal.  I have a couple of old bench meters like this and one has to be careful not to short out a voltage source when changing modes.

I really like the old Beckman RMS225 design where all three terminals, milliamps, amps, and volts-ohms, had the same spacing to the common terminal so standard 3/4 inch banana jacks could be used but these days only B&K and Amprobe/Wavetek/Meterman (they inherited Beckman's design) make meters like this.

Quote
Capacitor test function would be nice (pF and nF)

This is almost always useless; I never know when to trust it and it only works correctly for trivial cases.  Get a dedicated LCR meter like a DE-5000 or impedance bridge (if you can stand using it) if testing capacitors is important.

Quote
Hold or Autohold function ± MIN MAX function

Some meters have a really slow minimum/maximum function.  Do not count on this to capture power line voltage spikes.

Quote
other basic essentials

One of my old Beckman meters had a bipolar transistor hfe test function which I miss.  This is not as useful as it used to be unless you are still using leaded parts.

Temperature measurement using standard type K thermocouples is nice to have.  This is better if a dedicated thermocouple socket is used instead of an adapter but either are acceptable until the adapter is lost.

One of my high end meters supports separate average, RMS, *and* RMS AC+DC measurements which is very handy for doing calibration.

Wide bandwidth AC and RMS AC measurements are needed sometimes; better meters top out at 100kHz but I would not mind finding one which went higher.

You might not be able to get everything you want in a single meter and it may not even be preferable.  Consider an inexpensive meter which has more special functions and a more expensive meter that is higher performance.  Maybe buy the inexpensive meter first to get some experience so you know better what you want.

The problem is that I don't have a wide range of choices and many of them are not that satisfying.
Quote
There is as yet insufficient data for a meaningful answer."
Isaac Asimov
 

Online David Hess

  • Super Contributor
  • ***
  • Posts: 16614
  • Country: us
  • DavidH
Re: Help buying my first digital multimeter
« Reply #9 on: May 10, 2017, 04:00:01 pm »
The problem is that I don't have a wide range of choices and many of them are not that satisfying.

That is why I included my last suggestion.  No multimeter has every feature that I would prefer but between a high end one for basic precision measurements and a low end one for the special stuff, I can get pretty close.

Do not get stuck on requiring high accuracy at high expense for your first meter.  And for a first meter, I would prefer decent quality to exaggerated and questionable specifications.
 
The following users thanked this post: Sepehr

Offline daybyter

  • Frequent Contributor
  • **
  • Posts: 397
  • Country: de
Re: Help buying my first digital multimeter
« Reply #10 on: May 10, 2017, 10:27:24 pm »
You did not give any info on your electronics projects, but for repairing household stuff almost any somewhat safe DMM should be good enough. I wouldn't spend all my money on one tool. You might need other stuff, like a soldering station etc.
So I'd guess a cheaper DMM like the uni-t 139c should do the job for now.
 
The following users thanked this post: Sepehr

Offline Electro Detective

  • Super Contributor
  • ***
  • Posts: 2715
  • Country: au
Re: Help buying my first digital multimeter
« Reply #11 on: May 11, 2017, 12:14:08 am »
David Hess pretty much covered all bases in comments above   :-+

I can only suggest that if it was my first meter I would go for the blue EEVblog multimeter because it should do most of what you need, the price is fair,

and any technical support you may need is more or less located ummm... HERE!   :clap:

I would also suggest (when your pocket allows) getting a decent working analogue multimeter too, it does not have to be expensive or cheap cheap either. 

and an affordable digital clamp meter, preferably with low current AC RMS and DC clamp ability.

You can also use the 3 meters to check each other that they all agree, in case one fails due to failing battery, damage, faulty or wrong connections, blown fuse due to current blunders, and everyone's favourite >  user error   ;)   


An 'in circuit' ESR meter is a nice 'must have', but not if you're not familiar with just how easy it can be obliterated by a charged or sneaky recovering capacitor, or when surrounded by adjacent components. All ESR meters are not equal btw, some work well, some so so..

FWiW family and friends are always stressed as to what Christmas, Easter and Birthday gifts to buy, so if you play the 'suggestion' game right, you might have all 3 meters in under 12 months,  debt free    8)

« Last Edit: May 11, 2017, 12:32:41 am by Electro Detective »
 
The following users thanked this post: Sepehr

Offline karoru

  • Regular Contributor
  • *
  • Posts: 196
  • Country: pl
Re: Help buying my first digital multimeter
« Reply #12 on: May 11, 2017, 12:57:10 am »
Autoranging used to be a premium feature but I think today it is just a way to make a less expensive meter.  And with autoranging, manual ranging is more complicated and takes more time.  The difference is insignificant.

To be honest I can't stand that slow autoranging in 4000 count cheap multimeters, if I want to measure resistance I tend do just grab some oldie ICL7106 meter and dial in the range, goes much faster than either autorange starting from the beginning 5 times whilst fiddling with probes and me looking at decimal dot flying around, or me pressing "Range" button 10 times because I've overshoot to wrong range;)
 

Offline Electro Detective

  • Super Contributor
  • ***
  • Posts: 2715
  • Country: au
Re: Help buying my first digital multimeter
« Reply #13 on: May 11, 2017, 02:36:22 am »
Autoranging used to be a premium feature but I think today it is just a way to make a less expensive meter.  And with autoranging, manual ranging is more complicated and takes more time.  The difference is insignificant.

To be honest I can't stand that slow autoranging in 4000 count cheap multimeters, if I want to measure resistance I tend do just grab some oldie ICL7106 meter and dial in the range, goes much faster than either autorange starting from the beginning 5 times whilst fiddling with probes and me looking at decimal dot flying around, or me pressing "Range" button 10 times because I've overshoot to wrong range;)

Same boat here   :-+  I'm not sure if Autorange (AutoWAIT?) on any brand meter has EVER done me any favours,
I always end up having to go to a manual range to get any speedy stable readings and especially to use a MIN-MAX or PEAK feature.

If I'm having a 'bad bench day' rather than treat the Autorange meter like a nagging alarm clock, I'll grab a manual range meter and clicketty click click clack on the dial, DONE! 

Autorange sucks in most situations with cheap or overpriced meters. On my Fluke 189 in DC mode, the Autorange freezes, panics or locks up at the border crossing from one particular range to the next,
I can't remember exactly which, but was easily repeatable, and not a one off event.   
There is no fault with the meter, it's just this one annoying thing it does that Fluke missed at the testing stage IMHO. 

Autorange is a MUST HAVE for electronics noobs, and clueless probe prodding home workshop DIY cheapskates  :-[ 

EDIT: there are times when Autorange is handy, to let you know what the initial potentials are you are dealing with, 
but hey, you should already have a clue anyway, and dial up the highest VOA setting, to be sure !   
« Last Edit: May 13, 2017, 08:20:46 am by Electro Detective »
 

Offline karoru

  • Regular Contributor
  • *
  • Posts: 196
  • Country: pl
Re: Help buying my first digital multimeter
« Reply #14 on: May 11, 2017, 02:56:39 am »
For home workshop DIY prodders I always advice an electrical tester, like Uni-T 15C - it measures voltage & continuity without pushing/dialing/poking anything and has NCV integrated. There's no way to do anything funny with it.

For "electronic noobs" to be honest I'm not so sure "autoranging is a must". If I don't have at least rough idea about what order of magnitude value thing I'm measuring should be, then I shouldn't probably measure the damn thing as how I am going to interpret the result?
I work at Uni in CS department, and have EE one "next door". After renovating the basic electronics lab and buying stacks of nice multimeters (some Sanwas, don't remember exact model) and running the "Fundamentals of electronics" for 1st year students course once they changed meters back to ICL7106 ones because with "smart" meters it was a disaster. Half of lab reports tended to be absolutely screwed up - people messing up mV with V, not noticing that range on meter changed and drawing for example IV curve of diode looking like in the middle of measurement diode exploded and failed short.
 

Offline Electro Detective

  • Super Contributor
  • ***
  • Posts: 2715
  • Country: au
Re: Help buying my first digital multimeter
« Reply #15 on: May 11, 2017, 03:15:49 am »
Totally agree, I have a Fluke T-100, similar to the Uni-T, I can loan to prodding DIY heroes,
and they can prod along and beep beep away, feeling like they too can be professional   :clap: 

(and less thinking for me  ::))

And yes, students and anyone serious about electronics should learn on a manual range meter,
and get familiar with Autorange and analogue meters as well,
to get the big picture and be able to jump on to any meter and use it easily.
 

Offline SepehrTopic starter

  • Contributor
  • Posts: 20
  • Country: ir
Re: Help buying my first digital multimeter
« Reply #16 on: May 11, 2017, 07:03:25 am »
You did not give any info on your electronics projects, but for repairing household stuff almost any somewhat safe DMM should be good enough. I wouldn't spend all my money on one tool. You might need other stuff, like a soldering station etc.
So I'd guess a cheaper DMM like the uni-t 139c should do the job for now.
I'll mostly work with microcontrollers, Arduino, FPGA, etc.
I can only suggest that if it was my first meter I would go for the blue EEVblog multimeter because it should do most of what you need, the price is fair,

and any technical support you may need is more or less located ummm... HERE!   :clap:

I would also suggest (when your pocket allows) getting a decent working analogue multimeter too, it does not have to be expensive or cheap cheap either. 

and an affordable digital clamp meter, preferably with low current AC RMS and DC clamp ability.
Yes, I love buying something from EEVblog and yes that's a fair price but I'm not sure how much does shipping cost...
Why analog? where do they come in handy? also for clamp meters in electronics.
Autorange is a MUST HAVE for electronics noobs, and clueless probe prodding home workshop DIY cheapskates. 
So you mean it's a pain in the ass for professionals?
UT61E as main electronics meter, and a Fluke 101 as electrical meter. If you don't measure mains or your local mains is very clean (free of large transients), then you can use a single UT61E.
Still, I recommend 2 meters, just in case you need a second meter.
Thanks. Which one is better for doing electronics? UT139C or UT61E?
Quote
There is as yet insufficient data for a meaningful answer."
Isaac Asimov
 

Offline P90

  • Frequent Contributor
  • **
  • Posts: 640
Re: Help buying my first digital multimeter
« Reply #17 on: May 11, 2017, 07:18:06 am »
if you need data logging and higher display  resolution, get the ut61e
if you want temperature measurement and  better input protection get the ut139c
 
The following users thanked this post: Sepehr

Offline Paul Moir

  • Frequent Contributor
  • **
  • Posts: 926
  • Country: ca
Re: Help buying my first digital multimeter
« Reply #18 on: May 11, 2017, 07:26:40 am »
UT-61E - Data out, 22,000 count, Bargraph.  Note:  the count isn't indicative of accuracy, but sometimes you just need precision.
UT-139C - Temperature, 6000 count, Backlight.

That's what I think it boils down to.  In deference to many, I'll make the argument that backlights are not important.

P90 beat me.  :)
« Last Edit: May 11, 2017, 07:29:01 am by Paul Moir »
 
The following users thanked this post: Sepehr

Offline SepehrTopic starter

  • Contributor
  • Posts: 20
  • Country: ir
Re: Help buying my first digital multimeter
« Reply #19 on: May 11, 2017, 07:42:17 am »
Ah, I can't find those two UNI-T models locally  :-// or at least easily... I have to dig up the market to find them wich is not as easy as you may guess.
Looks like I can buy only the HIOKI one amongst Kyoritsu and Lutron...
Some people said that the Chinese manufacturers have free shippings, does that include UNI-T?
How can I contact Dave for information on shippings to Iran?
« Last Edit: May 11, 2017, 07:45:01 am by Sepehr »
Quote
There is as yet insufficient data for a meaningful answer."
Isaac Asimov
 

Offline Shock

  • Super Contributor
  • ***
  • Posts: 4214
  • Country: au
Re: Help buying my first digital multimeter
« Reply #20 on: May 11, 2017, 07:48:32 am »
Isn't there trade restrictions still with Iran?

As the government subsidizes shipping in China a they are able to do free shipping on small parcels if they wish to a lot of western countries (US, Australia, Europe etc). It's a reciprocal agreement and our countries postal service bear a large slice of the cost.

Not sure about Iran though. But if it was easy to buy from China you would surely know about it by now you're practically neighbors.
« Last Edit: May 11, 2017, 08:03:18 am by Shock »
Soldering/Rework: Pace ADS200, Pace MBT350
Multimeters: Fluke 189, 87V, 117, 112   >>> WANTED STUFF <<<
Oszilloskopen: Lecroy 9314, Phillips PM3065, Tektronix 2215a, 314
 

Offline Paul Moir

  • Frequent Contributor
  • **
  • Posts: 926
  • Country: ca
Re: Help buying my first digital multimeter
« Reply #21 on: May 11, 2017, 07:52:46 am »
For some countries maybe.  I'm sure you can get a UNI-T shipped off aliexpress?
(Yes, you will not likely find a UNI-T locally, and if you do not for a good price.  Even here in North America we get them from where they are made.)
 

Offline P90

  • Frequent Contributor
  • **
  • Posts: 640
Re: Help buying my first digital multimeter
« Reply #22 on: May 11, 2017, 08:11:35 am »
what about www.tme.eu ?
 

Online David Hess

  • Super Contributor
  • ***
  • Posts: 16614
  • Country: us
  • DavidH
Re: Help buying my first digital multimeter
« Reply #23 on: May 11, 2017, 08:50:43 am »
An 'in circuit' ESR meter is a nice 'must have', but not if you're not familiar with just how easy it can be obliterated by a charged or sneaky recovering capacitor, or when surrounded by adjacent components. All ESR meters are not equal btw, some work well, some so so...

I am not a big fan of ESR meters.  For a given type of capacitor, ESR is roughly inversely proportional to capacitance so a little table or graph showing what the ESR should be is needed.  These meters work for detecting capacitors which are completely shot but I do not need an ESR meter to do that.

What I would find useful is a meter which measures dissipation of a capacitor in-circuit.  Dissipation varies over a much smaller range and does not depend on capacitance.  Datasheets list end of life dissipation although this is more of a guideline than a rule. :)

Autoranging used to be a premium feature but I think today it is just a way to make a less expensive meter.  And with autoranging, manual ranging is more complicated and takes more time.  The difference is insignificant.

To be honest I can't stand that slow autoranging in 4000 count cheap multimeters, if I want to measure resistance I tend do just grab some oldie ICL7106 meter and dial in the range, goes much faster than either autorange starting from the beginning 5 times whilst fiddling with probes and me looking at decimal dot flying around, or me pressing "Range" button 10 times because I've overshoot to wrong range;)

I agree; some autoranging meters are cripplingly slow.  And I do not like cycling through the range button either; usually I pass the range I want at least once so I have to select the range twice.  I do not know if it is still the case but in the past, one of the distinguishing features of digital multimeters with autoranging was higher power consumption so lower battery life.

The last manual ranging meter I had was a Beckman Tech 310 and since that time, I got so used to autoranging meters that it was a pleasant surprise to use a manual ranging meter again when I picked up a pair of old Tektronix DM501 and DM502 bench multimeters.
 

Offline daybyter

  • Frequent Contributor
  • **
  • Posts: 397
  • Country: de
Re: Help buying my first digital multimeter
« Reply #24 on: May 11, 2017, 09:07:13 am »
Most of my Arduino stuff measurements here are done with a 2,74 bucks 830 dmm from aliexpress. It's a better one with the continuity buzzer and does the job most of the time. Not for work on mains, though.
I like the autorange of my ut 61e, when I check an unknown resistor as an example.
 

Offline karoru

  • Regular Contributor
  • *
  • Posts: 196
  • Country: pl
Re: Help buying my first digital multimeter
« Reply #25 on: May 11, 2017, 09:22:06 am »
So you mean it's a pain in the ass for professionals?
Don't be discouraged, autoranging is awesome feature, just some realizations of it (especially in low-end meters) leave much to be desired;)

I agree; some autoranging meters are cripplingly slow.
It never stops to amaze me that my boat anchor's Datron 1061A autorange that uses relays for range-switching works faster than some modern DMMs;)
« Last Edit: May 11, 2017, 09:28:41 am by karoru »
 

Offline Electro Detective

  • Super Contributor
  • ***
  • Posts: 2715
  • Country: au
Re: Help buying my first digital multimeter
« Reply #26 on: May 11, 2017, 10:17:23 am »
Autorange becomes the ultimate PITA when I need to get into MIN-MAX or PEAK MIN-MAX modes,
which of course only works if you're in the correct range to begin with to catch those sudden changes, otherwise the display reads "OL" 
or "LOL" if it's a really 'smart' meter  >:(

Anyone who has copped this min-max autorange experience in the middle of a job with their hands full, will know what I mean  :--

« Last Edit: May 11, 2017, 10:49:27 am by Electro Detective »
 

Offline P90

  • Frequent Contributor
  • **
  • Posts: 640
Re: Help buying my first digital multimeter
« Reply #27 on: May 11, 2017, 10:43:53 am »
An 'in circuit' ESR meter is a nice 'must have', but not if you're not familiar with just how easy it can be obliterated by a charged or sneaky recovering capacitor, or when surrounded by adjacent components. All ESR meters are not equal btw, some work well, some so so...

I am not a big fan of ESR meters.  For a given type of capacitor, ESR is roughly inversely proportional to capacitance so a little table or graph showing what the ESR should be is needed.  These meters work for detecting capacitors which are completely shot but I do not need an ESR meter to do that.

What I would find useful is a meter which measures dissipation of a capacitor in-circuit.  Dissipation varies over a much smaller range and does not depend on capacitance.  Datasheets list end of life dissipation although this is more of a guideline than a rule. :)

Autoranging used to be a premium feature but I think today it is just a way to make a less expensive meter.  And with autoranging, manual ranging is more complicated and takes more time.  The difference is insignificant.

To be honest I can't stand that slow autoranging in 4000 count cheap multimeters, if I want to measure resistance I tend do just grab some oldie ICL7106 meter and dial in the range, goes much faster than either autorange starting from the beginning 5 times whilst fiddling with probes and me looking at decimal dot flying around, or me pressing "Range" button 10 times because I've overshoot to wrong range;)

I agree; some autoranging meters are cripplingly slow.  And I do not like cycling through the range button either; usually I pass the range I want at least once so I have to select the range twice.  I do not know if it is still the case but in the past, one of the distinguishing features of digital multimeters with autoranging was higher power consumption so lower battery life.

The last manual ranging meter I had was a Beckman Tech 310 and since that time, I got so used to autoranging meters that it was a pleasant surprise to use a manual ranging meter again when I picked up a pair of old Tektronix DM501 and DM502 bench multimeters.


I think I still have one of those Beckman meters somewhere, must be around 30 years old...
 

Offline rsjsouza

  • Super Contributor
  • ***
  • Posts: 5986
  • Country: us
  • Eternally curious
    • Vbe - vídeo blog eletrônico
Re: Help buying my first digital multimeter
« Reply #28 on: May 11, 2017, 11:34:56 am »
Thanks, everyone. I had looked that spreadsheet, but it lacks some models that I can buy locally.
I'd like to know your comments on HIOKI DT-4211 as it's the only non-Chinese brand that I can buy although there are Fluke 101 and 106 and 15B which are made in China and some people claim that the 15B model is not very accurate and it has low autoranging and updating speed. Fluke 101 and 106 have much fewer functions on them compared to HIOKI DT-4211.
I don't have the Hioki, but it looks almost identical to the DER EE DR-241 (apart from a few button changes, which could well be set in software). Given it has a set of features that are useful for electronics (µA, frequency, duty cycle, capacitance, relative measures) and a few limitations that are not terribly important for this role (True RMS, 4000 counts), I say you wouldn't be wrong buying it.

Having lived in a country where the offers were extremely limited (especially due to the absurd prices), I always drooled over the offers and prices available in foreign markets. However, my thought process was: if I had the money (or had the means to save) I would try to pursue the higher quality that is locally available. That also reminds me of another advantage of the Hioki: it uses regular AA batteries (9V batteries were very expensive).

 
Vbe - vídeo blog eletrônico http://videos.vbeletronico.com

Oh, the "whys" of the datasheets... The information is there not to be an axiomatic truth, but instead each speck of data must be slowly inhaled while carefully performing a deep search inside oneself to find the true metaphysical sense...
 
The following users thanked this post: Sepehr

Offline P90

  • Frequent Contributor
  • **
  • Posts: 640
Re: Help buying my first digital multimeter
« Reply #29 on: May 11, 2017, 12:12:50 pm »
Thanks, everyone. I had looked that spreadsheet, but it lacks some models that I can buy locally.
I'd like to know your comments on HIOKI DT-4211 as it's the only non-Chinese brand that I can buy although there are Fluke 101 and 106 and 15B which are made in China and some people claim that the 15B model is not very accurate and it has low autoranging and updating speed. Fluke 101 and 106 have much fewer functions on them compared to HIOKI DT-4211.
I don't have the Hioki, but it looks almost identical to the DER EE DR-241 (apart from a few button changes, which could well be set in software). Given it has a set of features that are useful for electronics (µA, frequency, duty cycle, capacitance, relative measures) and a few limitations that are not terribly important for this role (True RMS, 4000 counts), I say you wouldn't be wrong buying it.

Having lived in a country where the offers were extremely limited (especially due to the absurd prices), I always drooled over the offers and prices available in foreign markets. However, my thought process was: if I had the money (or had the means to save) I would try to pursue the higher quality that is locally available. That also reminds me of another advantage of the Hioki: it uses regular AA batteries (9V batteries were very expensive).

I hate penlight batteries, in my experience they leak way too often, and I've never had a 9V leak...
 

Online David Hess

  • Super Contributor
  • ***
  • Posts: 16614
  • Country: us
  • DavidH
Re: Help buying my first digital multimeter
« Reply #30 on: May 11, 2017, 12:19:59 pm »
I think I still have one of those Beckman meters somewhere, must be around 30 years old...

Mine died from being left in a hot car on the dashboard which caused the LCD to turn black.  It was still sort of visible so I gave it to someone in need of a multimeter and replaced it with one of the Beckman Circuitmate meters although I do not remember which one.

I hate penlight batteries, in my experience they leak way too often, and I've never had a 9V leak...

I prefer AA and AAA cells to 9 volt batteries but the leakage problem is real.  9 volt alkaline batteries are made up internally of 6 almost AAA size cells so in effect they are double packaged which helps contain any leakage.
 

Offline P90

  • Frequent Contributor
  • **
  • Posts: 640
Re: Help buying my first digital multimeter
« Reply #31 on: May 11, 2017, 12:50:15 pm »
I think I still have one of those Beckman meters somewhere, must be around 30 years old...

Mine died from being left in a hot car on the dashboard which caused the LCD to turn black.  It was still sort of visible so I gave it to someone in need of a multimeter and replaced it with one of the Beckman Circuitmate meters although I do not remember which one.

I hate penlight batteries, in my experience they leak way too often, and I've never had a 9V leak...

I prefer AA and AAA cells to 9 volt batteries but the leakage problem is real.  9 volt alkaline batteries are made up internally of 6 almost AAA size cells so in effect they are double packaged which helps contain any leakage.

Left it in a hot car... that's like cruelty to meters... poor thing... lol
I've got a Wavekek (Beckman) rms225 circa mid 90's... don't recall the accuracy spec's, but it was a rugged meter, as were most of those Beckman multimeters...


 

Offline rsjsouza

  • Super Contributor
  • ***
  • Posts: 5986
  • Country: us
  • Eternally curious
    • Vbe - vídeo blog eletrônico
Re: Help buying my first digital multimeter
« Reply #32 on: May 11, 2017, 12:51:42 pm »
Thanks, everyone. I had looked that spreadsheet, but it lacks some models that I can buy locally.
I'd like to know your comments on HIOKI DT-4211 as it's the only non-Chinese brand that I can buy although there are Fluke 101 and 106 and 15B which are made in China and some people claim that the 15B model is not very accurate and it has low autoranging and updating speed. Fluke 101 and 106 have much fewer functions on them compared to HIOKI DT-4211.
I don't have the Hioki, but it looks almost identical to the DER EE DR-241 (apart from a few button changes, which could well be set in software). Given it has a set of features that are useful for electronics (µA, frequency, duty cycle, capacitance, relative measures) and a few limitations that are not terribly important for this role (True RMS, 4000 counts), I say you wouldn't be wrong buying it.

Having lived in a country where the offers were extremely limited (especially due to the absurd prices), I always drooled over the offers and prices available in foreign markets. However, my thought process was: if I had the money (or had the means to save) I would try to pursue the higher quality that is locally available. That also reminds me of another advantage of the Hioki: it uses regular AA batteries (9V batteries were very expensive).

I hate penlight batteries, in my experience they leak way too often, and I've never had a 9V leak...
Leaking batteries is a manageable problem - just don't leave the meter alone for too much time with them inside. Having to pay for a single 9V battery the equivalent of 8x~12x the price of a pair of AA batteries is really painful.
Vbe - vídeo blog eletrônico http://videos.vbeletronico.com

Oh, the "whys" of the datasheets... The information is there not to be an axiomatic truth, but instead each speck of data must be slowly inhaled while carefully performing a deep search inside oneself to find the true metaphysical sense...
 

Offline SepehrTopic starter

  • Contributor
  • Posts: 20
  • Country: ir
Re: Help buying my first digital multimeter
« Reply #33 on: May 11, 2017, 12:58:21 pm »
I don't have the Hioki, but it looks almost identical to the DER EE DR-241 (apart from a few button changes, which could well be set in software). Given it has a set of features that are useful for electronics (µA, frequency, duty cycle, capacitance, relative measures) and a few limitations that are not terribly important for this role (True RMS, 4000 counts), I say you wouldn't be wrong buying it.

Having lived in a country where the offers were extremely limited (especially due to the absurd prices), I always drooled over the offers and prices available in foreign markets. However, my thought process was: if I had the money (or had the means to save) I would try to pursue the higher quality that is locally available. That also reminds me of another advantage of the Hioki: it uses regular AA batteries (9V batteries were very expensive).
Yes, I've seen in another topic where they related it to that DER EE. I don't know why? Why do people relate them? I know they are identical, but what does this mean? Does it mean it's a cheap copy or poorly made device?
The EEVblog multimeter itself would cost exactly the same as the HIOKI, but I'm not aware of shipping costs, etc.
Quote
There is as yet insufficient data for a meaningful answer."
Isaac Asimov
 

Offline P90

  • Frequent Contributor
  • **
  • Posts: 640
Re: Help buying my first digital multimeter
« Reply #34 on: May 11, 2017, 01:05:56 pm »
DER EE is Taiwanese company and makes great products.
 

Offline rsjsouza

  • Super Contributor
  • ***
  • Posts: 5986
  • Country: us
  • Eternally curious
    • Vbe - vídeo blog eletrônico
Re: Help buying my first digital multimeter
« Reply #35 on: May 11, 2017, 01:53:53 pm »
I don't have the Hioki, but it looks almost identical to the DER EE DR-241 (apart from a few button changes, which could well be set in software). Given it has a set of features that are useful for electronics (µA, frequency, duty cycle, capacitance, relative measures) and a few limitations that are not terribly important for this role (True RMS, 4000 counts), I say you wouldn't be wrong buying it.

Having lived in a country where the offers were extremely limited (especially due to the absurd prices), I always drooled over the offers and prices available in foreign markets. However, my thought process was: if I had the money (or had the means to save) I would try to pursue the higher quality that is locally available. That also reminds me of another advantage of the Hioki: it uses regular AA batteries (9V batteries were very expensive).
Yes, I've seen in another topic where they related it to that DER EE. I don't know why? Why do people relate them? I know they are identical, but what does this mean? Does it mean it's a cheap copy or poorly made device?
The EEVblog multimeter itself would cost exactly the same as the HIOKI, but I'm not aware of shipping costs, etc.
It is not uncommon that some companies agree to have a share of their product line being designed and manufactured by other companies in an ODM regime (Original Design Manufacturer).

In this particular case, having a similar product on the market indicates the design is not from Hioki but instead from DER EE.

What does that mean in practical terms? Well, in this case it means the highly known original company (Hioki) subcontracted a lesser known brand (DER EE) to manufacture this product for unknown reasons - it could be cost or it could be inexperience in the particular market entry-level segment or something completely different. That may mean a good or a bad thing (it is a bad thing in case of Extech, for example). However, as P90 mentioned and shown in several other threads around eevblog regarding other products, DER EE seems to be a very reputable company that manufactures good quality products. 
Vbe - vídeo blog eletrônico http://videos.vbeletronico.com

Oh, the "whys" of the datasheets... The information is there not to be an axiomatic truth, but instead each speck of data must be slowly inhaled while carefully performing a deep search inside oneself to find the true metaphysical sense...
 
The following users thanked this post: Sepehr

Offline X

  • Regular Contributor
  • *
  • Posts: 179
  • Country: 00
    • This is where you end up when you die...
Re: Help buying my first digital multimeter
« Reply #36 on: May 11, 2017, 03:44:28 pm »
Your list is solid, but may not need all those items, so I have separated them based on your application, and annotated it. I have even added some items. Ensure you have at least the essentials. If your budget allows, the handy items will make your life a lot easier.

I do not know what you have access to in Iran so hopefully this helps:

Essentials
Manual range selection.
At least 2000-count, preferrably 4000 plus.
• High display updating and autoranging speed
• Basic DC volts accuracy of at least 0.5% Be sure the number of counts is also specified.
• It should have an AC or DC volts range of 200mV up to say, 1000V (NOT those designed for electricians)
• Ohms range of 200? up to 20M? Aim for at least 10mOhm resolution. Be aware of test lead resistance.
• Microamps and/or Milliamps Aim for at least 10uA resolution.
• Input impedance of at least 10M? It must be consistent throughout the ranges, (eg. should not
change from 10M in the 200mV range to 8M in the 2V range)

• A decent continuity test function (not delayed or scratched tone)
• Burden voltage 1mV/mA or 0.1 mV/?A You may get away with 10mV/mA or 10mV/A max.
• Capacitor test function would be nice (pF and nF) Try for at least 1000uF range as well. For low values, the capacitance added by the leads will change as you move the meter and leads, so be careful here.

Safety Essentials
Minimum CAT-II rating of 500VAC/500VDC.
• Separate terminals like (A-mA ?A-COM-V?) not (V?mA)
• HRC fuses not glass fuses

Handy to have
High-speed bargraph, updated many times faster than the numerical reading.
• REL function (Relative Measurement) If unavailable, mathematics may be good enough.
• Hold or Autohold function ± MIN MAX function
• It should have Autoranging feature and it'd be nice to have the feature of selecting between Manual and Autoranging
• Maximum test voltage of 4V for diode test Not strictly necessary, and can be achieved by discrete means if really necessary. Good to have a diode tester of at least 1.5V though.
• A reasonable and acceptable battery life Not a primary concern here, but be wary of anything lower than 100 hours.
Like, glow-in-the-dark buttons, man.

As for the alkaleak scenario mentioned by several others, lithium cells may be the solution.
« Last Edit: May 11, 2017, 03:54:55 pm by X »
 
The following users thanked this post: Sepehr

Online David Hess

  • Super Contributor
  • ***
  • Posts: 16614
  • Country: us
  • DavidH
Re: Help buying my first digital multimeter
« Reply #37 on: May 11, 2017, 04:36:58 pm »
Left it in a hot car... that's like cruelty to meters... poor thing... lol

It was my first digital multimeter so I plead inexperience.

Quote
I've got a Wavekek (Beckman) rms225 circa mid 90's... don't recall the accuracy spec's, but it was a rugged meter, as were most of those Beckman multimeters...

Based on the date codes, my RMS225 was produced in late 1990.  The feature I like the most about it that I miss in other multimeters is the banana socket arrangement where all of the inputs, volts-ohms, amps, and milliamps, support using a 3/4 inch banana plug to common.  This makes it easy to wire it into a circuit for continuous monitoring.
 

Offline rsjsouza

  • Super Contributor
  • ***
  • Posts: 5986
  • Country: us
  • Eternally curious
    • Vbe - vídeo blog eletrônico
Re: Help buying my first digital multimeter
« Reply #38 on: May 11, 2017, 06:46:43 pm »

Quote
I've got a Wavekek (Beckman) rms225 circa mid 90's... don't recall the accuracy spec's, but it was a rugged meter, as were most of those Beckman multimeters...

Based on the date codes, my RMS225 was produced in late 1990.  The feature I like the most about it that I miss in other multimeters is the banana socket arrangement where all of the inputs, volts-ohms, amps, and milliamps, support using a 3/4 inch banana plug to common.  This makes it easy to wire it into a circuit for continuous monitoring.
Funny you mentioned that. My UT136C has the same arrangement of inputs.
Vbe - vídeo blog eletrônico http://videos.vbeletronico.com

Oh, the "whys" of the datasheets... The information is there not to be an axiomatic truth, but instead each speck of data must be slowly inhaled while carefully performing a deep search inside oneself to find the true metaphysical sense...
 

Offline stj

  • Super Contributor
  • ***
  • Posts: 2155
  • Country: gb
Re: Help buying my first digital multimeter
« Reply #39 on: May 11, 2017, 07:27:49 pm »
banggood ships to iran.
how you get the money to them is another issue!

https://www.banggood.com/UNI-T-UT61E-Auto-Range-Modern-Digital-Multimeters-AC-DC-Meter-p-90124.html
 

Online David Hess

  • Super Contributor
  • ***
  • Posts: 16614
  • Country: us
  • DavidH
Re: Help buying my first digital multimeter
« Reply #40 on: May 11, 2017, 08:38:59 pm »
Funny you mentioned that. My UT136C has the same arrangement of inputs.

Like I posted earlier, B&K and Amprobe/Wavetek/Meterman also make some like that.  Unfortunately multimeters with this feature are all lower performance although not necessarily lower quality.
 

Offline karoru

  • Regular Contributor
  • *
  • Posts: 196
  • Country: pl
Re: Help buying my first digital multimeter
« Reply #41 on: May 12, 2017, 01:20:10 am »
Fluke 101 as electrical meter

Anything indicating that electrons wanting to visit earth are present that one can stick to his or her wall socket/distribution box without a chance for it to be a low impedance:)
 

Offline SepehrTopic starter

  • Contributor
  • Posts: 20
  • Country: ir
Re: Help buying my first digital multimeter
« Reply #42 on: May 12, 2017, 07:20:20 pm »
Isn't there trade restrictions still with Iran?

As the government subsidizes shipping in China a they are able to do free shipping on small parcels if they wish to a lot of western countries (US, Australia, Europe etc). It's a reciprocal agreement and our countries postal service bear a large slice of the cost.

Not sure about Iran though. But if it was easy to buy from China you would surely know about it by now you're practically neighbors.
I don't know, but it's very hard or expensive to buy something from foreign online shops for personal use as an average individual.  |O
For some countries maybe.  I'm sure you can get a UNI-T shipped off aliexpress?
(Yes, you will not likely find a UNI-T locally, and if you do not for a good price.  Even here in North America we get them from where they are made.)
We don't have an official access to financial companies like PayPal, MasterCard, etc so payments are a big turn down. However, it is possible to do online payments using MasterCard or other cards traded by private companies (gift cards I guess) but like other things I've said, they are absurdly priced and with no official support thus making me finally give up on shopping online from foreign websites. There are also many problems in shippings to a third world country in which I am...  :--
what about www.tme.eu ?
I guess I'd be better off not to shop online when there are the problems I said above.
Most of my Arduino stuff measurements here are done with a 2,74 bucks 830 dmm from aliexpress. It's a better one with the continuity buzzer and does the job most of the time. Not for work on mains, though.
I like the autorange of my ut 61e, when I check an unknown resistor as an example.
That's a promising thing to hear!
I see you're located in Germany, why don't you use those brilliant gems from Gossen Metrawatt?
So you mean it's a pain in the ass for professionals?
Don't be discouraged, autoranging is awesome feature, just some realizations of it (especially in low-end meters) leave much to be desired;)
Yes, I understand. Thank you.
Autorange becomes the ultimate PITA when I need to get into MIN-MAX or PEAK MIN-MAX modes,
which of course only works if you're in the correct range to begin with to catch those sudden changes, otherwise the display reads "OL" 
or "LOL" if it's a really 'smart' meter  >:(
LOL :-DD
[...] However, as P90 mentioned and shown in several other threads around eevblog regarding other products, DER EE seems to be a very reputable company that manufactures good quality products.
Thanks a lot for your reply. You explained it very well.  :-+
banggood ships to iran.
how you get the money to them is another issue!

https://www.banggood.com/UNI-T-UT61E-Auto-Range-Modern-Digital-Multimeters-AC-DC-Meter-p-90124.html
Thanks for the suggestion, but you guessed it right.

OK, guys. I think there would be no benefit in waiting at this point. I'm going to buy something as a starter, maybe I move on to better DMMs later whenever I find something on the market.  ???

I have to somehow make a choice from this list, I don't know about the reputation of the SANWA one among users, but I like to know your thoughts on which one you would prefer.

There are more items that I can buy, including Kyoritsu and Lutron and some models of the UNI-T and LINI-T, but I guess they are not good enough. Also, this list has been made mostly by looking up in the local online shops while I have had found some of the items in the local shops too.
SANWA CD771
GPS-176
VICTOR 88C
VICTOR 86D
HIOKI DT4212 (although this one is beyond my budget...)
HIOKI DT4211
Fluke 15B

Thanks in advance  :)
« Last Edit: May 12, 2017, 07:22:45 pm by Sepehr »
Quote
There is as yet insufficient data for a meaningful answer."
Isaac Asimov
 

Offline Electro Detective

  • Super Contributor
  • ***
  • Posts: 2715
  • Country: au
Re: Help buying my first digital multimeter
« Reply #43 on: May 13, 2017, 06:51:17 am »
If you can't get a decent feature packed performance meter like the EEVblog meter, I was about to suggest the Fluke 15B meter would be an excellent first meter,
but... according to the Fluke website   http://www.fluke.com/Fluke/inen/Digital-Multimeters/Fluke-15B.htm?PID=56017

it seems you may have to be Indian to be able to use it!  ???  Perhaps it has an Ethnicity Sensor sensor built in, and may not switch on ...?!  :-//


" 15B DMMs
With the launch of 15B Digital Multimeters in India, Fluke offers features most often needed for troubleshooting most of day to day electrical and electronics problems.
The 15B DMM is specially designed for Indian technicians keeping in mind their requirements for quick and easy troubleshooting.

15B offers features like AC/DC voltage measurement along with functions like diode test, capacitance measurement and continuity detection. In addition to above.

Simple to use and large LCD display along with many other user friendly benefits makes the 15B DMM a true companion, no doubt they have become first choice of today’s maintenance and field engineers. 15B DMM is highly affordable and is easily available through a wide network of retail stockiest across India.
   
"

Sorry I wasn't much help      ;)
 
The following users thanked this post: Sepehr

Offline SepehrTopic starter

  • Contributor
  • Posts: 20
  • Country: ir
Re: Help buying my first digital multimeter
« Reply #44 on: May 13, 2017, 11:17:08 am »
If you can't get a decent feature packed performance meter like the EEVblog meter, I was about to suggest the Fluke 15B meter would be an excellent first meter,
but... according to the Fluke website   http://www.fluke.com/Fluke/inen/Digital-Multimeters/Fluke-15B.htm?PID=56017

it seems you may have to be Indian to be able to use it!  ???  Perhaps it has an Ethnicity Sensor sensor built in, and may not switch on ...?!  :-//


" 15B DMMs
With the launch of 15B Digital Multimeters in India, Fluke offers features most often needed for troubleshooting most of day to day electrical and electronics problems.
The 15B DMM is specially designed for Indian technicians keeping in mind their requirements for quick and easy troubleshooting.

15B offers features like AC/DC voltage measurement along with functions like diode test, capacitance measurement and continuity detection. In addition to above.

Simple to use and large LCD display along with many other user friendly benefits makes the 15B DMM a true companion, no doubt they have become first choice of today’s maintenance and field engineers. 15B DMM is highly affordable and is easily available through a wide network of retail stockiest across India.
   
"

Sorry I wasn't much help      ;)
:-DD
I like your sense of humor!
Quote
There is as yet insufficient data for a meaningful answer."
Isaac Asimov
 
The following users thanked this post: Electro Detective

Offline rsjsouza

  • Super Contributor
  • ***
  • Posts: 5986
  • Country: us
  • Eternally curious
    • Vbe - vídeo blog eletrônico
Re: Help buying my first digital multimeter
« Reply #45 on: May 13, 2017, 02:43:51 pm »
The Sanwa and the Hioki 4211 are very similar. The Sanwa has a battery tester (which I find useful) and the Hioki has a frequency measurement(which I fund much more useful, especially for electronics). IMHO the Hioki has the best balance between features and quality in your selection.
Vbe - vídeo blog eletrônico http://videos.vbeletronico.com

Oh, the "whys" of the datasheets... The information is there not to be an axiomatic truth, but instead each speck of data must be slowly inhaled while carefully performing a deep search inside oneself to find the true metaphysical sense...
 
The following users thanked this post: Sepehr

Offline SepehrTopic starter

  • Contributor
  • Posts: 20
  • Country: ir
Re: Help buying my first digital multimeter
« Reply #46 on: May 13, 2017, 03:37:33 pm »
The Sanwa and the Hioki 4211 are very similar. The Sanwa has a battery tester (which I find useful) and the Hioki has a frequency measurement(which I fund much more useful, especially for electronics). IMHO the Hioki has the best balance between features and quality in your selection.
What's a battery tester? Does it measure its capacity?
Can't you test a battery by measuring its voltage?
Quote
There is as yet insufficient data for a meaningful answer."
Isaac Asimov
 

Offline rstofer

  • Super Contributor
  • ***
  • Posts: 9890
  • Country: us
Re: Help buying my first digital multimeter
« Reply #47 on: May 13, 2017, 04:01:53 pm »
The Sanwa and the Hioki 4211 are very similar. The Sanwa has a battery tester (which I find useful) and the Hioki has a frequency measurement(which I fund much more useful, especially for electronics). IMHO the Hioki has the best balance between features and quality in your selection.
What's a battery tester? Does it measure its capacity?
Can't you test a battery by measuring its voltage?

Open circuit voltage is nice to know but it doesn't say anything about the internal resistance or very much about the state of charge.  A better test would be to place a rated load across the battery while measuring the voltage.  As that load would vary by battery type, a DMM might just put some nominal load on the battery.  Battery datasheets have information on rated discharge (and charge) currents.
 
The following users thanked this post: Sepehr

Offline rsjsouza

  • Super Contributor
  • ***
  • Posts: 5986
  • Country: us
  • Eternally curious
    • Vbe - vídeo blog eletrônico
Re: Help buying my first digital multimeter
« Reply #48 on: May 13, 2017, 10:58:29 pm »
The Sanwa and the Hioki 4211 are very similar. The Sanwa has a battery tester (which I find useful) and the Hioki has a frequency measurement(which I fund much more useful, especially for electronics). IMHO the Hioki has the best balance between features and quality in your selection.
What's a battery tester? Does it measure its capacity?
Can't you test a battery by measuring its voltage?

Open circuit voltage is nice to know but it doesn't say anything about the internal resistance or very much about the state of charge.  A better test would be to place a rated load across the battery while measuring the voltage.  As that load would vary by battery type, a DMM might just put some nominal load on the battery.  Battery datasheets have information on rated discharge (and charge) currents.
As rstofer said, batteries sometimes have their internal resistance increased by a large factor - however, still negligible when compared to the DMM's input resistance of 10M ohms. The practical effect is that, when such battery is measured by the DMM, its voltage may be very close to the 1,5V of a new battery. The battery tester on the Samwa puts a 30ohm resistor in parallel with the DMM input, therefore simulating a scenario where the battery is in an active circuit. This helps evaluate if the internal resistance is high (the voltage reading is much lower) and if the battery has not much charge left (the voltage read decreases at a fast rate). Despite not being extremely accurate, as these factors depend of the size of the battery, this serves as a quick check.
Vbe - vídeo blog eletrônico http://videos.vbeletronico.com

Oh, the "whys" of the datasheets... The information is there not to be an axiomatic truth, but instead each speck of data must be slowly inhaled while carefully performing a deep search inside oneself to find the true metaphysical sense...
 
The following users thanked this post: Sepehr

Offline rstofer

  • Super Contributor
  • ***
  • Posts: 9890
  • Country: us
Re: Help buying my first digital multimeter
« Reply #49 on: May 14, 2017, 12:46:42 am »
In a plant where I worked, we had a diesel generator that wouldn't start.  The open circuit battery voltage was fine but dropped immediately to 0v when the start button was pressed.  In this case, I was using a V-O-M so the motion of the needle was all I needed to see.  I didn't need a lot of digits of accuracy, all I wanted to see was the delta V.



 

Offline Electro Detective

  • Super Contributor
  • ***
  • Posts: 2715
  • Country: au
Re: Help buying my first digital multimeter
« Reply #50 on: May 14, 2017, 02:54:20 am »
Quote from: ]

 [b
The battery tester on the Samwa puts a 30ohm resistor in parallel with the DMM input[/b], therefore simulating a scenario where the battery is in an active circuit. This helps evaluate if the internal resistance is high (the voltage reading is much lower) and if the battery has not much charge left (the voltage read decreases at a fast rate). Despite not being extremely accurate, as these factors depend of the size of the battery, this serves as a quick check.

30 ohm resistor?  or 3k ohm that some meters have for Low-Z/ghost voltage nuking?
« Last Edit: May 14, 2017, 02:56:29 am by Electro Detective »
 

Offline rsjsouza

  • Super Contributor
  • ***
  • Posts: 5986
  • Country: us
  • Eternally curious
    • Vbe - vídeo blog eletrônico
Re: Help buying my first digital multimeter
« Reply #51 on: May 14, 2017, 03:32:01 am »
Zlow is a different beast. I have never seen a battery checker have such high resistance, given this would yield only 500uA in a fresh battery.

At any rate, that is what is shown in the Sanwa manual.
Vbe - vídeo blog eletrônico http://videos.vbeletronico.com

Oh, the "whys" of the datasheets... The information is there not to be an axiomatic truth, but instead each speck of data must be slowly inhaled while carefully performing a deep search inside oneself to find the true metaphysical sense...
 

Offline P90

  • Frequent Contributor
  • **
  • Posts: 640
Re: Help buying my first digital multimeter
« Reply #52 on: May 14, 2017, 03:55:37 am »
yup, lo-z is low input impedance, and the battery test function is just a small load to take off the surface charge of a battery under test.
 

Offline Electro Detective

  • Super Contributor
  • ***
  • Posts: 2715
  • Country: au
Re: Help buying my first digital multimeter
« Reply #53 on: May 14, 2017, 04:14:34 am »
Thanks for the clarification gents,

I use the Low Z mode to occasionally test batteries (and test trip RCD/GFIs)

It's not as good as my battery tester, but if I see a significant difference between Low Z and standard Volts DC readings, the battery gets swapped out.

 

Offline SeanB

  • Super Contributor
  • ***
  • Posts: 16281
  • Country: za
Re: Help buying my first digital multimeter
« Reply #54 on: May 14, 2017, 10:46:49 am »
Thanks for the clarification gents,

I use the Low Z mode to occasionally test batteries (and test trip RCD/GFIs)

It's not as good as my battery tester, but if I see a significant difference between Low Z and standard Volts DC readings, the battery gets swapped out.



I have a somewhat well used Tadiran 3V primary lithium cell that expired around 2 decades ago, but which has not leaked, and which still has an open circuit ( into 10M) voltage over 3V. However, loading it with 1M will drop the voltage to under 2V.

I was using it in a chime mechanism for around 5 years, simply by having 100 000uF of capacitor ( 2 47000uF 16V electrolytics) across the cell, but eventually the cell was taking over an hour to recharge the capacitor after the hour had been played, and it was warbling. Put in some white mystery AA cells after ( glade air freshener batteries that come in the pack, I had been buying the starter packs instead of the refills, because the starter pack came with 2 refills and the dispenser, at the price of a single refill can) that, and yesterday changed them out again, after probably a year of use after they no longer would run the dispenser motor.  Now have some Duracell AA cells in there, hopefully good till 2026.
 


Share me

Digg  Facebook  SlashDot  Delicious  Technorati  Twitter  Google  Yahoo
Smf