Tonghui TH2821A LCR Meter

Here's something that may interest some folks here. I just got my new 
Tonghui TH2821A LCR Meter, and I'm starting to become quite impressed. 

After some screwups due to a discharged internal battery and not reading 
the instructions, it is starting to give some really impressive results. 

5 digits resolution on 1000uf caps, 4 digits on iron-core inductor, 
miscellaneous resolution on 30k resistors (I haven't figured out how to 
measure resistance yet, but it should be very easy:)

Here's the eBay info:

  LCR RCL LC Meter TH2821A inductance Capacitance 10kHz

  Price    : US $164.93
  Shipping : $25.00
  Item     : 320492041898

  It can  measure  6 basic parameters:  inductance  L,  capacitance C,
  resistance R,  impedance Z, dissipation factor D and  quality factor
  Q.

  It has measurement accuracy of 0.3% and 4-bin sorting.

  Applied complete 5-terminal measurement configuration solves problem
  of measurement  for equivalent series resistance and  capacitor with
  small dissipation that other portable LCR meters can't solve. It can
  replace general low-frequency LCR meter.

  Only portable LCR meter at home
  Large LCD display
  Measurement frequency up to 10kHz
  Basic accuracy: 0.3% with resolution of 0.01%
  5-side measurement technology to provide accurate measurement of ESR 
and loss
  Sweep Clear Function
  battery and external power supply power supply
  fourth gear sorting

  Measurement Signal

  Signal Frequency : 100Hz 120Hz 1KHz,10KHz
  OutPut Impedance : Dependent on range
  Test level       : 0.3Vrms

  Measurement display range

  R   : 0.0001Ohm ~ 99.999Ohm
  C   : 0.01pF ~ 9999uF
  L   : 0.01uH ~ 9999H
  D,Q : 0.0001 ~ 9.9999
  ?%  : -999.99% ~ 999.99%

  Comparator

  Comparator : 4bins: NG, P1, P2, P3 with beeper alarm

  You can also get smd tongs:

  LCR METER-SMD/CLIP,TWEEZERS,TH26029 FOR TONGHUI, 
  US $36.00
  
  Item : 350502463639

The manual is dated November 2005, 1st Edition Rev 1.0.0

"http://www.pinsonne-elektronik.de/media/daten/TH2821A%20Operation%
20Manual.pdf"

Specifications

"http://www.ekt2.com/_files/40%20TONGHUI%20TH2821.pdf"

Datasheet

"http://www.aet.com.pl/Portals/0/katalogi_pdf/maszyny_zalewy_impregnaty/m
ostki_rlc/th2821.pdf"

You can also get the TH2821B, which goes to 1KHz

Item: 350501591362
 
Price: US $136.00

The only problem so far is they shipped a 220VAC adapter, which does not 
work on 120VAC. After some discussions, they shipped a universal 100-
240VAC adapter which should work anywhere. If you want one, be sure and 
tell them to ship the universal 100-240VAC adapter. But they are very 
nice to deal with and you should have no problems.

For the performance and price, I don't think you can beat this anywhere. 
I especially like being able to measure ESR of large electrolytics, since 
I have a lot of eBay boat anchors that need some care.

So far the performance is excellent. I'll post if I come across any 
surprises.

Regards,

Mike

I bought something like this. There are variations.

Ebay
220766760779

$40.00 with shipping.

High Precision L/C Inductance Capacitance Digital Meter

Specification:

Measurement accuracy:    1%
Capacitance Measuring range:  0.01pF~10uF
Minimum resolution:   0.01pF
Inductance Measuring Range:  0.001uH ~ 100mH
Large Inductance Measuring Range:  0.001mH ~ 100H
Minimum resolution:  0.001uH
Test Frequency:   about 500Hz
LCD effective display digits:  4
Display Method:  1602 LCD
Power Supply:  Mini USB interface, 5V interface
Size: 81 x 47 x 30 mm ( L*W*H )

I power it up using my scope USB port.

Most of my apps don't require accuracy.
For say around 50nH then I set up a generator and a scope.

Cheap! Cheap! Cheap!

Mike <spam@me.not> wrote:

> 5 digits resolution on 1000uf caps, 4 digits on iron-core inductor, 
> miscellaneous resolution on 30k resistors (I haven't figured out how
> to measure resistance yet, but it should be very easy:)

The resistance measurements are now OK once the internal battery is 
charged. This issue is mentioned in the manual. The unit comes with the 
battery discharged, so you just have to wait until it is charged before 
starting to play with it.

It gives 4 digits of resolution on a 30k resistor. This is adequate for 
most ordinary needs.

Altogether, I'm very pleased. It has already identified a bad electrolytic 
in a circuit where there are several that could be causing the problem. The 
rest are fine.

Mike

Mike <spam@me.not> wrote:

The TH2821A appears to be discontinued, but there may still be some stock 
left on eBay. 

The replacement is the TH2822C, which goes up to 100KHz and offers 
averaging, 40,000 counts, 16 hours operation on internal battery, TH2822C 
has optional rechargeable batteries,  Standard Mini-USB interface, etc.

Here's the feature list:

  * Basic measurement accuracy: 0.25% 
  * Gorgeous dual-color cast shell
  * Maximum test signal frequency: 100kHz (TH2822C)
  * 40,000 counts for primary parameter, D/Q resolution 0.0001
  * Typical ultra-low consumption : 25mA
  * Battery capacity: TH2822/TH2822A continuously used for 16 hours
  * TH2822C rechargeable batteries are optional
  * Innovatively compatible terminal configuration : 5-terminal test
  slot and 3-terminal banana jack
  * Intelligent Auto LCR function
  * Measurement speed up to 4 meas/sec 
  * fast automatic range switch design
  * Constant output impedance: 100 Ohm
  * Percentage display and 4-tolerance comparator: 1%, 5%, 10%,
  20% (20% not available for TH2822)
  * Automatic OPEN/SHORT correction detection
  * Data Hold, Max/Min/ Average recording
  * Utility function configuration and current setup recovery after
  power-off
  * Standard Mini-USB interface, SCPI compatible
  * Firmware update through Mini-USB interface
  * Free FastAccess communication software on our website

The web page is

http://www.tonghui.com.cn/en/goods/index/250.html

The TH2822C are vailable on eBay for around $474.70

It looks like the TH2821A is a pretty good deal for the price, if you can 
still get one:)

Thanks,

Mike

On 11/1/2011 10:06 PM, Mike wrote:
> Mike<spam@me.not>  wrote:
>
> The TH2821A appears to be discontinued, but there may still be some stock
> left on eBay.
>
> The replacement is the TH2822C, which goes up to 100KHz and offers
> averaging, 40,000 counts, 16 hours operation on internal battery, TH2822C
> has optional rechargeable batteries,  Standard Mini-USB interface, etc.
>
> Here's the feature list:
>
>    * Basic measurement accuracy: 0.25%
>    * Gorgeous dual-color cast shell
>    * Maximum test signal frequency: 100kHz (TH2822C)
>    * 40,000 counts for primary parameter, D/Q resolution 0.0001
>    * Typical ultra-low consumption : 25mA
>    * Battery capacity: TH2822/TH2822A continuously used for 16 hours
>    * TH2822C rechargeable batteries are optional
>    * Innovatively compatible terminal configuration : 5-terminal test
>    slot and 3-terminal banana jack
>    * Intelligent Auto LCR function
>    * Measurement speed up to 4 meas/sec
>    * fast automatic range switch design
>    * Constant output impedance: 100 Ohm
>    * Percentage display and 4-tolerance comparator: 1%, 5%, 10%,
>    20% (20% not available for TH2822)
>    * Automatic OPEN/SHORT correction detection
>    * Data Hold, Max/Min/ Average recording
>    * Utility function configuration and current setup recovery after
>    power-off
>    * Standard Mini-USB interface, SCPI compatible
>    * Firmware update through Mini-USB interface
>    * Free FastAccess communication software on our website
>
> The web page is
>
> http://www.tonghui.com.cn/en/goods/index/250.html
>
> The TH2822C are vailable on eBay for around $474.70
>
> It looks like the TH2821A is a pretty good deal for the price, if you can
> still get one:)
>
> Thanks,
>
> Mike

You talked me into it, Mike. The specs look super to me and I've been 
needing something like it.

Do you get probes with it so you can test components on a populated board?

Thanks for the find.

John S

  John S <sophi.2@invalid.org> wrote:

  > You talked  me into it, Mike. The specs look super to me  and I've
  > been needing something like it.

  > Do you  get  probes  with  it so  you  can  test  components  on a
  > populated board?

  > Thanks for the find.

  > John S

  Which one are you getting - TH2821A or TH2822C?

  The SMD  probe  I  mentioned  earlier  is  for  the  TH2821A.  It is
  available on eBay:

  LCR METER-SMD/CLIP, TWEEZERS, TH26029 FOR TONGHUI,
  Price: US $36.00
  Item : 350502463639

  It won't  work  on the TH2822, but they should  have  something that
  does work.

  For populated  boards,  of  course   you  have  to  watch  for other
  components in  parallel. But the measuring voltage seems  to  be too
  low to  turn  on  silicon junctions, so it should  work  OK  in most
  situations.

  I was  afraid of accidentally testing a charged  electrolytic, which
  is how  I destroyed my last capacitance meter. So I  tried  adding a
  fast silicon diode in parallel with a large electrolytic.

  As far as I can tell, it has little or no effect on the reading. But
  it makes  the  instrument  go nuts  when  there  is  no electrolytic
  capacitor to  measure. I will make a little test  fixture  that adds
  two fast 3A diodes back-to-back in parallel with the test  probes to
  try to avoid making the same mistake in the future.

  I find  sometimes the reading on the TH2821A fluctuates  a  bit. You
  have to  find the correct test frequency for the  component  you are
  trying to measure.

  I would  really like the ability to average the  readings,  which is
  provided in the TH2822C. But the price is way more than I am willing
  to pay.

  Once it gets to that level, I seriously start thinking of  making my
  own unit. With the components available to us these days,  it should
  be possible  to  beat  the performance  of  almost  anything  on the
  market.

  For example, there are two vector network analyzers available on the
  web that  you can build yourself. Both are in the Yahoo  forums, and
  they seem  to be very good instruments. But already there is  a much
  better version  of the DDS than the one they are using.  That should
  improve the performance substantially.

  There is  also  a spectrum analyzer you can  build  yourself.  But I
  happen to have a 8566 so that is not too interesting at the moment.

  The only problem is if the 8566 dies and needs some unobtanium part.

  That already  happened to a HP 8505 network analyzer  that  I bought
  new, and was discontinued the week after I paid cash for it.  It ran
  for a number of years, then it died. It would have cost too  much to
  get it repaired, so I just put it in a dumpster and  promised myself
  I would  never  buy another expensive instrument. Either  get  it on
  eBay for pennies, or build it myself.

  Ultimately I would rather have my own stuff. It will take  much less
  room on  the  bench,  have usb interface for  control,  and  be much
  easier to repair or upgrade as time goes on.

  Regards,

  Mike

About four years ago I purchased a similar unit, the MCP BR2822 LCR
http://www.mcpsh.com/BR2821%20BR2822.html
I paid $250 for it and except for some problems with the battery, it =
seemed=20
OK. But I have not used it much. I think I got it from these guys:
http://www.multimeterwarehouse.com/BR2822.htm,
who now want $349 for it. Amazon has it for $300.
http://www.amazon.com/MCP-BR2822-Professional-10KHz-Digital/product-revie=
ws/B000TYUZM0

I also bought a $50 LCR that I use for everyday purposes:
http://www.amazon.com/Sinometer-MS8222H-Digital-Multimeter-Meter/dp/B000M=
FIDC0.
It's OK, but sometimes I have to fiddle with the switch and/or the leads =
to=20
get continuity.

I'm waiting for delivery on:
http://www.ebay.com/itm/ws/eBayISAPI.dll?ViewItem&item=3D190450842291&ssP=
ageName=3DADME:L:OU:US:1123
and
http://www.ebay.com/itm/ws/eBayISAPI.dll?ViewItem&item=3D190452347958&ssP=
ageName=3DADME:L:OU:US:1123

I'm considering the following unit:
http://www.ebay.com/itm/320780815383?ssPageName=3DSTRK:MEWAX:IT&_trksid=3D=
p3984.m1423.l2649
or maybe this:
http://www.ebay.com/itm/330633195250?ssPageName=3DSTRK:MEWAX:IT&_trksid=3D=
p3984.m1423.l2649

Paul

"P E Schoen" <paul@pstech-inc.com> wrote:

> About four years ago I purchased a similar unit, the MCP BR2822 LCR
> http://www.mcpsh.com/BR2821%20BR2822.html
> I paid $250 for it and except for some problems with the battery, it
> seemed OK. But I have not used it much. I think I got it from these
> guys: http://www.multimeterwarehouse.com/BR2822.htm,
> who now want $349 for it. Amazon has it for $300.
> http://www.amazon.com/MCP-BR2822-Professional-10KHz-Digital/product-rev
> iews/B000TYUZM0 

That looks identical to the TH2821A!

> I also bought a $50 LCR that I use for everyday purposes:
> http://www.amazon.com/Sinometer-MS8222H-Digital-Multimeter-Meter/dp/B00
> 0MFIDC0. It's OK, but sometimes I have to fiddle with the switch
> and/or the leads to get continuity.

Yes, I have a bunch of dmms. Some measure capacitance, but none measure 
ESR. You need that to weed out the bad electrolytics in eBay boat 
anchors.

> I'm waiting for delivery on:
> http://www.ebay.com/itm/ws/eBayISAPI.dll?ViewItem&item=190450842291&ssP
> ageName=ADME:L:OU:US:1123 and
> http://www.ebay.com/itm/ws/eBayISAPI.dll?ViewItem&item=190452347958&ssP
> ageName=ADME:L:OU:US:1123 
> 
> I'm considering the following unit:
> http://www.ebay.com/itm/320780815383?ssPageName=STRK:MEWAX:IT&_trksid=p
> 3984.m1423.l2649 or maybe this:
> http://www.ebay.com/itm/330633195250?ssPageName=STRK:MEWAX:IT&_trksid=p
> 3984.m1423.l2649 
> 
> Paul

For the function generator, I've pretty much decided to go ahead and make 
my own using a DDS. You can get microhertz resolution, 0 to 250MHz sine 
waves, and USB interface. I think you can get frequency sweep and other 
functions, and add your own limiter for square waves. Put two in the same 
box for intermodulation testing and mixer development. Add external 
filters for high purity sine waves for harmonic distortion. Run it off a 
GPS-stabilized reference for the ultimate in frequency stability.

The main thing is you can't predict what you may want to do, so having 
the flexibiity to modify your own generator is much better than getting a 
commercial unit that may not have the fundamental accuracy and stability 
you need. You might be reluctant to modify a commercial unit, or maybe 
you don't even get the schematics. But if it's your own, that is no 
problem.

Thanks,

Mike

On 11/2/2011 10:21 PM, Mike wrote:
>    John S<sophi.2@invalid.org>  wrote:
>
>    >  You talked  me into it, Mike. The specs look super to me  and I've
>    >  been needing something like it.
>
>    >  Do you  get  probes  with  it so  you  can  test  components  on a
>    >  populated board?
>
>    >  Thanks for the find.
>
>    >  John S
>
>    Which one are you getting - TH2821A or TH2822C?

TH2821A

>    The SMD  probe  I  mentioned  earlier  is  for  the  TH2821A.  It is
>    available on eBay:
>
>    LCR METER-SMD/CLIP, TWEEZERS, TH26029 FOR TONGHUI,
>    Price: US $36.00
>    Item : 350502463639

Thanks. I'll look into it.

John S

On 11/2/2011 10:21 PM, Mike wrote:
>    John S<sophi.2@invalid.org>  wrote:
>
>    >  You talked  me into it, Mike. The specs look super to me  and I've
>    >  been needing something like it.
>
>    >  Do you  get  probes  with  it so  you  can  test  components  on a
>    >  populated board?
>
>    >  Thanks for the find.
>
>    >  John S
>
>    Which one are you getting - TH2821A or TH2822C?
>
>    The SMD  probe  I  mentioned  earlier  is  for  the  TH2821A.  It is
>    available on eBay:
>
>    LCR METER-SMD/CLIP, TWEEZERS, TH26029 FOR TONGHUI,
>    Price: US $36.00
>    Item : 350502463639
>

BTW, these are also available for those large, TH electrolytics already 
on the board:

Item 320702317637

Cheers,
John S