Author Topic: XJW01 Auto LCR meter review ($120 bench top LCR meter)  (Read 44051 times)

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Offline AG7CK

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Re: XJW01 Auto LCR meter review ($120 bench top LCR meter)
« Reply #75 on: June 15, 2018, 10:52:13 am »
 :-DD :-DD :-DD

Well, 2x50Hz is 100Hz and 2x60Hz is 120Hz, so it all depends on the grid line frequency of the country in which the datasheet was written or which it was written for.

But it doesn't mean anything at all. Start read some manuals, and you will soon know it all.

 ;D
 

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Re: XJW01 Auto LCR meter review ($120 bench top LCR meter)
« Reply #76 on: June 15, 2018, 11:11:13 am »
And which manuals would they be?
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Offline AG7CK

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Re: XJW01 Auto LCR meter review ($120 bench top LCR meter)
« Reply #77 on: June 15, 2018, 11:38:53 am »
And which manuals would they be?

Thank you for asking. I will compile a list of imo useful and easy to read manuals below. In the mean time:

1) Please search the web for "lcr 100hz 120hz". You will find snippets like:

- 100Hz and 120 Hz test frequencies are generally used in capacitance measurement of electrolytic capacitors which are used as power line voltage rectifiers.

- UK— 50 Hz - Ripple frequency = 100 Hz

- to filter power line frequency effects (50/100Hz or 60/120Hz)

- Test frequencies: 100Hz, 120Hz, 1kHz and 10kHz.

This will set you off finding info yourself.


2) Read the very good manual for DE-5000 (a very good cheap all-round instrument). There are different versions, but this was the first I found: https://www.ietlabs.com/pdf/Manuals/DE_5000_im.pdf

If you search "100 Hz" in the pdf-file manual, you will find the string "100 Hz / 120 Hz / 1 kHz / 10 kHz / 100 kHz" on page 46 of 52.


3) Now go search "100 Hz / 120 Hz / 1 kHz / 10 kHz / 100 kHz" on the web, and you will get "a ton" of user manuals for LCR meters.


Voila, I don't have to compile a list after all ... (joking, I will put up a list later).

Good luck searching and reading.
 

Offline buildafriend

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Re: XJW01 Auto LCR meter review ($120 bench top LCR meter)
« Reply #78 on: June 15, 2018, 11:41:18 am »
:=\ :=\ :=\

Impedance  = Voltage / Current = Potential / Current

(Force) Current High and Low : Hc, Lc
(Sense) Potential High and Low : Hp, Lp

The search "lcr lp lc hc hp" gives (on my pc, i.e. - ymmv) first link being: http://hiokiusa.com/wp-content/uploads/pdf/28261-LCRappguide-2016.pdf . On page 5 of 28 I find the below attached figure.

The excellent but excentric XJW01 is imo only for people who already know how to use a generic LCR meter already (yep, yhat is a double).

People w/o willingness and ability to search and learn on their own can imo use it to "indicate" some value or another for ohm, farad and henry - but little else.

Hence go find and study 3-10 user manuals for LCR meters from Japan, Germany and USA, and you will see that many questions in this thread evaporates into thin air.

 :-DMM
 :=\

The recently recommended paper on impedance measurement was extremely helpful, now you've got me digging. And yeah I wish I could afford a normal LCR meter before this one! There's no reason to settle for a lesser meter when you have the ability to learn a better one that costs less. Does this not count as research  ;) The old art of communicating with people ;D

This adds clarity, thank you!!
« Last Edit: June 15, 2018, 11:49:47 am by buildafriend »
E-Prime only
 

Offline WhichEnt2

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Re: XJW01 Auto LCR meter review ($120 bench top LCR meter)
« Reply #79 on: June 15, 2018, 11:44:44 am »
Quote
Well, 2x50Hz is 100Hz and 2x60Hz is 120Hz
Really? And why do you insidiously ignore 100 kHz in such complex math equations?
 :popcorn:
Short pieces, high value, small period, huge amount, long delay.
 

Offline AG7CK

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Re: XJW01 Auto LCR meter review ($120 bench top LCR meter)
« Reply #80 on: June 15, 2018, 12:04:57 pm »
Quote
Well, 2x50Hz is 100Hz and 2x60Hz is 120Hz
Really? And why do you insidiously ignore 100 kHz in such complex math equations?
 :popcorn:

I like your sense of humor. Pass me the popcorn, please.

I must admit that I cannot count to 100.000

But there are historical reasons for the universally accepted test frequencies of (all in Hz):

- 100/120 (explained over)

- 1k, 10k (standard caps and more - intermediate values)

- 100k (RF stuff)

But this is also searchable for those who bother to do it. So no need for me to write a half baked explanation of things that are already out there.

PS If you search the web for "eevblog xjw01 7.8khz" you will know the reason why this meter does not conform to 10kHz. And if you search the web for "lcr meter 9.6khz" you will learn even more.

Happy searching.
 

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Re: XJW01 Auto LCR meter review ($120 bench top LCR meter)
« Reply #81 on: June 15, 2018, 12:17:13 pm »
Quote
Well, 2x50Hz is 100Hz and 2x60Hz is 120Hz
Really? And why do you insidiously ignore 100 kHz in such complex math equations?
 :popcorn:

I like your sense of humor. Pass me the popcorn, please.

I must admit that I cannot count to 100.000

But there are historical reasons for the universally accepted test frequencies of (all in Hz):

- 100/120 (explained over)

- 1k, 10k (standard caps and more - intermediate values)

- 100k (RF stuff)

But this is also searchable for those who bother to do it. So no need for me to write a half baked explanation of things that are already out there.

PS If you search the web for "eevblog xjw01 7.8khz" you will know the reason why this meter does not conform to 10kHz. And if you search the web for "lcr meter 9.6khz" you will learn even more.

Happy searching.
So in the case of someone like me who is not really RF but more into audio and power supply smoothing and filtering the 100Hz and 120Hz testing frequency is surely just fine?

I have just read the manual for DE5000 and yes, while it does support 1KHz, 10KHz 100KHz, 100Hz and 120Hz, the default is 1KHz but it does not explain why it defaults to IHz test frequency and likewise it fails to mention why does it support other frequencies as well?
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Offline WhichEnt2

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Re: XJW01 Auto LCR meter review ($120 bench top LCR meter)
« Reply #82 on: June 15, 2018, 01:53:39 pm »
Quote
But this is also searchable for those who bother to do it. So no need for me to write a half baked explanation of things that are already out there.
Sure.

Quote
PS If you search the web for "eevblog xjw01 7.8khz"
This and other (decision not to use ICL7135) nuances of xjw01 design is clearly described in machine-translated doc for early revision of meter.

Quote
"lcr meter 9.6khz" you will learn even more.
Results is fully stuffed with some lcr meter which is made by Chroma. I learned that their manual for that meter and appnotes on lcr related info not nearly as good as same docs from HP / Keysight.
Very unexpectedly.
I'd bet you meant something about difficulties in implementation precise 10 k vs using just-close-enoguh don't-even-have-to-use-extrapolation 9.6 k.
« Last Edit: June 15, 2018, 01:57:18 pm by WhichEnt2 »
Short pieces, high value, small period, huge amount, long delay.
 
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Offline AG7CK

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Re: XJW01 Auto LCR meter review ($120 bench top LCR meter)
« Reply #83 on: June 15, 2018, 08:36:34 pm »
Well, I guess I should have kept my hands out of this hole of worms ...

When in my naivety I search "lcr meter why 9.6khz not 10khz" or similar, I get answers like '10 kHz = 9.6 kHz' even from an Agilent dokument:

Code: [Select]
[PDF]Agilent U1731B/U1732B Dual Display Handheld LCR Meter - Keysight
literature.cdn.keysight.com/litweb/pdf/U1731-90059.pdf
requirement. This affixed product label indicates that you must not .... The 20,000-count dual display
handheld LCR meters (U1731B and ...... 10 kHz = 9.6 kHz.
[PDF]878A and 879 Dual Display LCR Meter - Mouser Electronics
[url]https://www.mouser.com/ds/2/43/879_manual-707041.pdf[/url]
controlled meter for measuring functions of inductance, capacitance and ... Extremely simple to operate,
the instrument not only takes ..... 10KHz= 9.6 KHz.
[PDF]Tenma 72-1025 LCR Meter - UNC Physics
[url]https://users.physics.unc.edu/~sean/Phys351/techresource/docs/Tenma72-1025.pdf[/url]
Benchtop LCR Meter. Model 72-1025 ...... mode. The dark areas are not provided on this meter.
100Hz. 120Hz. 1KHz. 10KHz. Resistance .... 10KHz= 9.6 KHz.

.......

WTF ...

The reason why 10 kHz = 9.6 kHz and 7.8 kHz is close enough to 10 kHz, is probably related to microprocessor crystal frequencies and prescaler / divider factors (used for test oscillators).

So 100/120 - 10k/9.6k or 7.8k really doesn't matter. Start by choosing low frequency 100 (or 120) for PSU electrolytes, 1k/10k for micro- to nanofarad sized audio stuff and similar, and 100k for handfuls of picofarads.

The manual https://users.physics.unc.edu/~sean/Phys351/techresource/docs/Tenma72-1025.pdf over is good. Read it and go search on your own.

---ooo---

Edit:
Copy from http://literature.cdn.keysight.com/litweb/pdf/U1731-90059.pdf:

"
Test frequency accuracy:
±0.1%
...
100 Hz = 100 Hz
120 Hz = 120 Hz
1 kHz = 1010 Hz
10 kHz = 9.6 kHz
...
"
 
 :o
« Last Edit: June 15, 2018, 09:26:58 pm by AG7CK »
 

Offline nctnico

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Re: XJW01 Auto LCR meter review ($120 bench top LCR meter)
« Reply #84 on: June 15, 2018, 10:34:56 pm »
The recently recommended paper on impedance measurement was extremely helpful, now you've got me digging. And yeah I wish I could afford a normal LCR meter before this one! There's no reason to settle for a lesser meter when you have the ability to learn a better one that costs less. Does this not count as research  ;) The old art of communicating with people ;D
Define normal LCR meter. After I bought the XJW01 I also bought an old HP LCR meter (something with ...74) which supported 100kHz as well. It turned out the XJW01 is way more accurate especially for low values (like the milli-ohm range). Ofcourse no bias voltage but with a simple external circuit (DC blocking capacitor) you can add that to the XJW01 as well. End of story: the HP LCR has left the building.

I got a network analyser instead which can do frequency sweeps as well.
There are small lies, big lies and then there is what is on the screen of your oscilloscope.
 

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Re: XJW01 Auto LCR meter review ($120 bench top LCR meter)
« Reply #85 on: June 15, 2018, 10:57:16 pm »
The recently recommended paper on impedance measurement was extremely helpful, now you've got me digging. And yeah I wish I could afford a normal LCR meter before this one! There's no reason to settle for a lesser meter when you have the ability to learn a better one that costs less. Does this not count as research  ;) The old art of communicating with people ;D
Define normal LCR meter. After I bought the XJW01 I also bought an old HP LCR meter (something with ...74) which supported 100kHz as well. It turned out the XJW01 is way more accurate especially for low values (like the milli-ohm range). Ofcourse no bias voltage but with a simple external circuit (DC blocking capacitor) you can add that to the XJW01 as well. End of story: the HP LCR has left the building.

I got a network analyser instead which can do frequency sweeps as well.
Yes I believe that the XJW01 is pretty accurate and of course it has another big advantage over the HP LCR meter, size, the HP one is massive, its as big as a 1740A scope.
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Offline The Electrician

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Re: XJW01 Auto LCR meter review ($120 bench top LCR meter)
« Reply #87 on: June 16, 2018, 09:37:53 am »
And which manuals would they be?

This one is good: http://www.componentsengineering.com/wp-content/uploads/pdfs/LCR-Measurement-Primer.pdf
Yes thats a good one, but let me spin it on its head now, all of the ESR charts on capacitors that I've seen have all been on electrolytics and are taken at 100Hz or 120Hz. In fact on some LCR/ESR testers even have a table of expected results printed on them, and once again they are for electrolytics at the same frequencies.

Are tables for there tables that show what a good ESR reading should be at 100KHz and also at 10KHz for these other caps?

It has always been the case in my experience that these other caps like ceramics etc have 2 failure modes open or shorted circuited. The capacitance may drift a bit over time and this can checked on the testers but nowhere have I ever come across any form of a table or even a mention about the passable ESR values for these, nor have I heard anyone mention that this is a problem until this thread. So is this a consequence of the ever increasing frequencies being used today or what? 
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Offline The Electrician

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Re: XJW01 Auto LCR meter review ($120 bench top LCR meter)
« Reply #88 on: June 16, 2018, 09:10:27 pm »
And which manuals would they be?

This one is good: http://www.componentsengineering.com/wp-content/uploads/pdfs/LCR-Measurement-Primer.pdf
Yes thats a good one, but let me spin it on its head now, all of the ESR charts on capacitors that I've seen have all been on electrolytics and are taken at 100Hz or 120Hz. In fact on some LCR/ESR testers even have a table of expected results printed on them, and once again they are for electrolytics at the same frequencies.

Are tables for there tables that show what a good ESR reading should be at 100KHz and also at 10KHz for these other caps?

It has always been the case in my experience that these other caps like ceramics etc have 2 failure modes open or shorted circuited. The capacitance may drift a bit over time and this can checked on the testers but nowhere have I ever come across any form of a table or even a mention about the passable ESR values for these, nor have I heard anyone mention that this is a problem until this thread. So is this a consequence of the ever increasing frequencies being used today or what?

A long time ago in the first half of the 20th century, before computers, measuring capacitors was done with manual bridges; things that looked like this: https://www.bing.com/images/search?q=impedance+bridge&qpvt=impedance+bridge&FORM=IGRE

At that time 1 kHz was more or less a default frequency for measurement of caps.

After the second world war, there was a rapid increase in electronic technology and electrolytic capacitors became the standard item for ripple filtering in power supplies.  Since electrolytic caps were usually polarized, it was necessary to avoid applying a reverse voltage to them, but to measure them it was necessary to apply an AC voltage, and AC voltage goes negative for half the cycle; what to do?  As it happens, electrolytic caps don't mind a very small reverse voltage for a short time so the manufacturers got together and established a standard.  The standard was to apply an AC frequency similar to what the cap would see in use.  This would be double the grid frequency most of the time because of the common full wave rectifier circuits.  So the standard, still in use today, is to measure at 120 Hz (twice the 60 Hz grid frequency; 100 Hz in Europe, close enough) with an applied voltage of 1/2 volt RMS.

Since in the 1940's and 1950's when the standard was established, switching power supplies operating at frequencies above 20 kHz were almost non-existent, there was no need to know or measure ESR at those frequencies.  But, nowadays switchers are ubiquitous, and manufacturers of electrolytics intended for use in switchers specify impedance at 100 kHz.  The impedance and ESR of typical electrolytics have the same numerical value at 100 kHz, so measuring impedance is the same as measuring ESR.  This fact allows a low cost instrument to measure ESR; see the long thread I reference below for details about this.  The 100 kHz frequency is sort of in the middle range of commonly used switcher operating frequencies although megahertz switchers are looming.

So these are the reasons for 100 Hz, 120 Hz, 1 kHz and 100 kHz measurement frequencies.  But what about 10 kHz?  When the first low cost LCR meters were being designed, 100 kHz was enough harder to do than 10 kHz that 10 kHz was what you got.  It was still useful to get a better idea of capacitor parameters at switcher frequencies than just 1 kHz.  And a user might have another reason to measure at or near 10 kHz, and it's easy to include it in modern instruments.

Finally, LCR meters 20 years ago were still somewhat expensive and repair techs couldn't afford one.  But then someone noticed that at 100 kHz a typical electrolytic with capacitance of, say, 100 uF or more has a reactance much less than 1 ohm; .016 ohms for 100 uF and less for larger sizes.  Because the reactance is so low, it's common that the ESR will be greater than the reactance and so the reactance can be ignored when measuring the ESR.  At lower frequencies where the reactance is larger than the ESR, a phase sensitive detector must be used to measure ESR, and this increases the cost of the meter.  A method of using digital pulse techniques to measure ESR resulted in ESR meters costing much less than the typical LCR meter of the time.  One of the first was the "Blue ESR meter": https://anatekinstruments.com/products/fully-assembled-anatek-blue-esr-meter-besr

Many meters using this technique have been developed since then, and they are mainly useful to repair technicians (and hobbyists) to locate defective electrolytics.  Since the concept of ESR was not very useful to a repair tech when the only available meters cost many thousands of dollars, those techs were not familiar with what a good cap's ESR would be.  The availability of ESR meters that a repair tech could afford meant that somehow techs would have to know what good and bad ESR would be for various electrolytics.  Hence, tables of typical good ESR appeared: https://www.eevblog.com/forum/beginners/esr-values-for-electrolytic-caps/

People complain about these tables, rightly so, and in truth there is great variablilty in electrolytic capacitor ESR and the tables are really just useful as rough guidelines, which is better than nothing.  The best thing to do is measure the ESR of a known good sample of the electrolytic in question.

The price and capability of integrated circuits has continued to improve over the years, and now there are fully capable LCR meters available for about the same price as the pulse technique ESR meters, for example the DE5000.

I explain in detail about capacitor ESR here: https://www.eevblog.com/forum/projects/impedance-lcr-esr-meters/msg459303/#msg459303

Also have a look at this thread: https://www.eevblog.com/forum/projects/capacitor-measurements-on-an-impedance-analyzer/msg178362/#msg178362
 
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Re: XJW01 Auto LCR meter review ($120 bench top LCR meter)
« Reply #89 on: June 16, 2018, 10:52:07 pm »
Thank you thats very informative but that still doesn't solve the problem definitively because if I have correctly understood it, to effectively test a capacitor, you need to know what type of circuit it is being used. Take the case of power supply, there are many questions that need to answered before you can be certain if the capacitor under test is suitable not just at the time of being tested but also was it suitable for the application at the time of the PSU being designed and built?

You talk about switchers coming that will operate not in 10s or 100s of KHz but in MHz which is going to cloud the issue even further, do we even have capacitors that would be suitable for such switchers?

However, my main point still remains unanswered, speaking purely as a person who is primarily interested and involved in repairing items as opposed to designing and developing some new piece of equipment that is designed at high frequencies and maybe even running into the GHz regions. That would mean dealing with more mundane frequencies from 100Hz to 100Khz for switchers.  Where are the tables that show the acceptable ESR values for capacitors used in such instances in the discussion you refer to https://www.eevblog.com/forum/beginners/esr-values-for-electrolytic-caps/ there are many tables (sources are not quoted or the frequncies tested at), some of these tables are actually printed on the various test instruments, ie, the Blue meter and the BK tester. There is in that thread much debate and disagreement on how to test and what is and what isn't acceptable, so how are repair engineers/technicians like myself supposed to get it right?

The industry really needs a table that is fit for purpose and also proper testers that don't cost an arm and a leg or need massive amount of bench/shelf space that can test these capacitors correctly for the average consumer type of products, this must be a doable thing surely?

So what advice would you give in that instance and what tester would meet that requirement and why? If I read you correctly, you seem to advocate the DE-5000 but I have read the manual for that and it is very hard to understand and it doesn't even mention what frequency to test capacitors at, it just mentions what frequencies it is capable of providing which is useless in reality to most people, especially given that capacitor failure is one of the biggest if not the biggest cause of modern equipment failing.   

 
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Offline nctnico

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Re: XJW01 Auto LCR meter review ($120 bench top LCR meter)
« Reply #90 on: June 16, 2018, 11:12:44 pm »
When it comes to electrolytic capacitors then 100kHz is more than enough. If you want to make certain a capacitor from a (failed) circuit still meets it's specs you'll need to read it's datasheet and measure to see if it meets the specs or not.

For much higher frequencies you'll see Tantalum and MLCC capacitors. These fail open or short so any DMM with capacitance measurement ability is suitable to check these for value (unless ofcourse the value falls outside the measurement range).
There are small lies, big lies and then there is what is on the screen of your oscilloscope.
 

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Re: XJW01 Auto LCR meter review ($120 bench top LCR meter)
« Reply #91 on: June 16, 2018, 11:53:46 pm »
When it comes to electrolytic capacitors then 100kHz is more than enough. If you want to make certain a capacitor from a (failed) circuit still meets it's specs you'll need to read it's datasheet and measure to see if it meets the specs or not.

For much higher frequencies you'll see Tantalum and MLCC capacitors. These fail open or short so any DMM with capacitance measurement ability is suitable to check these for value (unless ofcourse the value falls outside the measurement range).
I don't use DMM's with capacitance range, they are always miles out, these are what I currently use and the highest known frequency is 7.8KHz on the XJW01, the frequency of the other 2 is not known.

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Offline nctnico

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Re: XJW01 Auto LCR meter review ($120 bench top LCR meter)
« Reply #92 on: June 17, 2018, 12:06:08 am »
The VC8145 DMMs I have are spot on down to the nf range using long wires.
« Last Edit: June 17, 2018, 12:15:57 am by nctnico »
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Re: XJW01 Auto LCR meter review ($120 bench top LCR meter)
« Reply #93 on: June 17, 2018, 12:33:15 am »
As far as I know, mine are also pretty much spot when it comes to measuring the capacitance, but what's more important to me is the ESR values.
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Offline SteveSi

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Re: XJW01 Auto LCR meter review ($120 bench top LCR meter)
« Reply #94 on: October 15, 2019, 04:17:45 pm »
Video here on how to use and what buttons do and what screen means, etc.
https://youtu.be/NgSRAg9lLYg#
 


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