LCR Meter compare, accuracy

[simonbaker]

I compared 3 LCR meters inductance measurement.

BK Precision 878A ($230)
Knight K-240C ($80)
Mastech MS8201H ($50)

I don't know which is most accurate, but chart shows comparison. My guess is to only trust inexpensive meters to be around 5 - 10% accurate in certain ranges.

-SB

[MaverickITA]

I am using a tester for measure the inductance.
It is called Sinometer model VC9808, the cost is low and it is easy to found in the market.
I compared the measure with a professional meter and I found a maximum of about 2,5% of difference but for many test the difference was less.
Professional inductance meters are very expensive!
My tester is enough for me for check coil values and do some compare.

[simonbaker]

I am using a tester for measure the inductance.
It is called Sinometer model VC9808, the cost is low and it is easy to found in the market.
I compared the measure with a professional meter and I found a maximum of about 2,5% of difference but for many test the difference was less.
Professional inductance meters are very expensive!
My tester is enough for me for check coil values and do some compare.

That's good to know. Some people not so happy though on Amazon.

On smallest capacitance range, is the reading perfectly steady, or is there some fluctuation, and if so, how much?

-SB

[MaverickITA]

Hi Simonbaker !

Thank you for the answer.

I am outside of my country for job reasons.
I have not the tester with me.
Therefore I can not do immediately the test that you propose.
I assure you that I will do the test as soon as I came back to my home.

Sorry, I can answer only in September 2009.
Please, stay tuned.

If you prefer, I am available to make also other tests and measures.

I am Italian, sorry for my (bad) english.

Ciao,
Maverick

[simonbaker]

Hi Simonbaker !

Thank you for the answer.

I am outside of my country for job reasons.
I have not the tester with me.
Therefore I can not do immediately the test that you propose.
I assure you that I will do the test as soon as I came back to my home.

Sorry, I can answer only in September 2009.
Please, stay tuned.

If you prefer, I am available to make also other tests and measures.

I am Italian, sorry for my (bad) english.

Ciao,
Maverick

I understand your English well, it is not bad.

Thank you for agreeing to test. I'm interested because my Mastech meter has some fluctuations in last digit on smallest capacitance range, can be as large as 4 to 6 units, it limits the precision. My Knight meter however is steady. For a few dollars more, your meter may be a better choice.

Cheers,

-SB

[MaverickITA]

Hi Simonbaker !

The K240C cost 10$ less if you buy directly from Knightedu.

However you can found datasheets and specs here:

http://www.bkprecision.com/products/...ls/?model=878A

http://www.knightedu.com/products/la...ti/K-240C.html

http://www.p-mastech.com/products/04_dm/ms8201h.html

Reading specs, I found MS8201H better than K240C, not only for inductance, but at all.

However BK878A is completely different.
It measure the inductance at multiple frequency and the precision is more accurate but only for value over 20mH.
Under 20mH at 120Hz or 2mH at 1KHz the precision is 2% very near to MS8201H (3%).
But BK878A is the only that measure also DF that is 1/Q.
The price instead is multiplied about five. It is very expensive.

The range value for PI coil are often under 1mH. Clone PI for example use about 0.4mH.
The range value for IB and VLF coil is are often between 1mH or a bit less and 20mH or more.
TGS, that you know, use coil around 6mH.
However the values depends from engineer that developed his idea (MD).
They are different from brand and model.

I think that BK is for a laboratory where you measure also transformer, EAT, toroid, choke, etc. etc. and not only MD coils.

However, before to buy one BK878A, I think is better to look and compare it with another instrument similar for price range, about 200/300$.
If you want, I can help you to do this but American market is different from European market.
Therefore I need others brand and model that you found easy in your country.
In other words, many instruments that I found easy in my country are not available in yours and viceversa.

Instead, if one person has a small budget, I suggest to buy MS8201H.
It is a general purpouse tester at a low cost and with competitive precision.

Kind regards,
Maverick

[simonbaker]

Hi Simonbaker !

The K240C cost 10$ less if you buy directly from Knightedu.

However you can found datasheets and specs here:

http://www.bkprecision.com/products/...ls/?model=878A

http://www.knightedu.com/products/la...ti/K-240C.html

http://www.p-mastech.com/products/04_dm/ms8201h.html

Reading specs, I found MS8201H better than K240C, not only for inductance, but at all.

However BK878A is completely different.
It measure the inductance at multiple frequency and the precision is more accurate but only for value over 20mH.
Under 20mH at 120Hz or 2mH at 1KHz the precision is 2% very near to MS8201H (3%).
But BK878A is the only that measure also DF that is 1/Q.
The price instead is multiplied about five. It is very expensive.

The range value for PI coil are often under 1mH. Clone PI for example use about 0.4mH.
The range value for IB and VLF coil is are often between 1mH or a bit less and 20mH or more.
TGS, that you know, use coil around 6mH.
However the values depends from engineer that developed his idea (MD).
They are different from brand and model.

I think that BK is for a laboratory where you measure also transformer, EAT, toroid, choke, etc. etc. and not only MD coils.

However, before to buy one BK878A, I think is better to look and compare it with another instrument similar for price range, about 200/300$.
If you want, I can help you to do this but American market is different from European market.
Therefore I need others brand and model that you found easy in your country.
In other words, many instruments that I found easy in my country are not available in yours and viceversa.

Instead, if one person has a small budget, I suggest to buy MS8201H.
It is a general purpouse tester at a low cost and with competitive precision.

Kind regards,
Maverick

Hi Maverick:

Thanks for your ideas and the time you spent finding and studying the specs.

I currently own the Knight and the Mastech meters I tested. I borrowed the BK to check the ones I own because they did not perfectly agree on measurements.

The Knight meter does not have as many functions as the Mastech, but the low ranges are better on Inductance and Capacitance and it seems like a better engineered product.

The Knight meter was always a little closer to the expensive BK than the Mastech. If you assume the BK was more accurate, then the Knight is more accurate than the Mastech for inductance. I did not have time to check other functions.

The BK was very nice to use I will say because it had autoranging and the more professional features.

I don't have money to get more meters, but it was an interesting test.

If you ever get a chance to test your meter against a very expensive one I would be interested in the results.

Regards,

-SB

[MaverickITA]

Hi Simonbaker !

I used the specs for compare.
They are papers, therefore only real tests tell you which is the best instruments.

But you know that the brands are different therefore they used different "champions" and methods for set their instruments.

You are assuming that BK is correct but I think is better to do tests in another way.
Take a lot of at least 3 champion inductances with values many different between them, turn on your meters, wait almost 10 minutes and do the measures at the same temperature, use ambient temperature, about 18/25 ºC, no more. Then compare them.

Perhaps, you will discover another situation.

In September I can repeat all tests but using other instruments and champions.

Kind regards,
Maverick

[simonbaker]

Hi Simonbaker !

I used the specs for compare.
They are papers, therefore only real tests tell you which is the best instruments.

But you know that the brands are different therefore they used different "champions" and methods for set their instruments.

You are assuming that BK is correct but I think is better to do tests in another way.
Take a lot of at least 3 champion inductances with values many different between them, turn on your meters, wait almost 10 minutes and do the measures at the same temperature, use ambient temperature, about 18/25 ºC, no more. Then compare them.

Perhaps, you will discover another situation.

In September I can repeat all tests but using other instruments and champions.

Kind regards,
Maverick

I agree. I don't conclude that BK is most accurate; but if it is, then Knight is more accurate than Mastech.

What is a "champion"? A reference?

I would like to take some stable inductors, capacitors, resistors and test with really good, expensive tester so I have a reference.

I know it isn't really important for this hobby, but we like to tune our test equipment just like our metal detectors!

It is an interesting problem to try to determine true measurement when you don't have any precise reference.

Regards,

-SB

[MaverickITA]

Hi Simonbaker !

Yes, champion is a reference.
It is not easy to found them and they are expensive.

Kind regards,
Maverick

[Max]

Hi Simonbaker !

Yes, champion is a reference.
It is not easy to found them and they are expensive.

Kind regards,
Maverick

Sator arepo tenet opera rotas ?

Hmmmm....

seems cryptic... but probably isn't much.

why you used the St. Peter's one ???

I like this one...it's better!

Kind regards,
Max

[MaverickITA]

Hi Max !

I live near church ...

http://en.wikipedia.org/wiki/Sator_Square

Regards

[Alexismex]

My best accurate Lcr meter will beat many of the commercial one
a joy to use :
http://www.aade.com/lcmeter.htm

Regards

[WM6]

I compared 3 LCR meters inductance measurement.

BK Precision 878A ($230)
Knight K-240C ($80)
Mastech MS8201H ($50)

I don't know which is most accurate, but chart shows comparison. My guess is to only trust inexpensive meters to be around 5 - 10% accurate in certain ranges.

-SB

It depend on used frequency, even expensive L-meter is not accurate if your in circuit aplied frequency and L-meter frequency are far away.

[jackflash43]

Mathematics

Inductance is a function of frequency. If the oscillator of the circuits is in the range of 10khz to 20khz, then my reading of test of coil in the 120hz and 1khz have a different value. The units described here all work in the 120hz or 1khz and we need to do a chart L vs F to find the behavior or this coil at the frequency my circuits work. The manufacturer use 1khz as a common value, however this coil at 10 or 15khz will have a value different.

The best meter is to do a traditional measurement with a oscillator in the frequency used, a scope and a rms meter to measure and with the formula find the L, Q and D of the coil using excel to do simulations at differents coil windings, diameter or wire size.