Shannon ST42 LCR Tweezer Test and Comparison Thread

[Martin72]

So, tested today.
I can't show the circuit board for obvious reasons, but you can trust me.
I chose an area where a lot of SMD components are "gathered", resistors and capacitors, including a large tantalum with 33µF.
Resistors were tested in RDC mode, which does not allow voltage reduction, neither on the Mastech nor on the Shannon.
Capacitors were tested at 0.5V and 1kHz.
Of 10 resistors tested, the ST42 was able to measure 9 correctly, as was the Mastech.
Of 10 capacitors tested, the ST42 could only measure 2 correctly, the Mastech only one.
This is rather sobering when you consider that the measurement in circuits was emphasized as a point.
However, I personally did not expect anything else.
I will draw my conclusions next weekend.

[KungFuJosh]

2:1 is still a win. 😉

Which mode did you test the capacitors in?

[Martin72]

Cs, 1kHz, 0.5V .

[KungFuJosh]

Was there any indication that trying Cp would help at all?

[Martin72]

I can repeat this with Cp, the problem of measuring in circuits remains the same.
For example, you have a filter capacitor at the supply voltage of the circuit and a support capacitor with a smaller value directly at a component supplied with it.
And you now want to measure this capacitor, but it is in parallel with the large filter capacitor.
What do you measure then, right, both.
That's why I wrote that I wasn't surprised by the result.
I would have been surprised if the ST42 had been able to measure a 100nF capacitor that was in parallel with a 10µF capacitor via a detour.
This simply does not work in principle and is not a technical fault.
However, you should then rethink your application for the device according to the realities and possibly leave it alone.
That's why my overall conclusion about the ST42 will be positive.

[KungFuJosh]

That makes perfect sense. I'm still curious about whether there's any perceivable effect changing the modes while testing in circuit.

Most things like that in circuit usually need to have one side lifted to be tested. It's cute when these type of devices think they can magically isolate the DUTs. Maybe someday the science will pass the magic thinking. 😉

[thm_w]

This is rather sobering when you consider that the measurement in circuits was emphasized as a point.

Usually when we talk about in circuit measurement for capacitors, its RC filters, series DC block caps, caps in opamp filter circuits, etc.
Or for repair, decoupling caps, often we can still measure the bulk value and its overall ESR. Reading the 100nF's value alone is generally not important.

Of course domain dependent as well, if its all ultra low <10pF values, then more likelyhood of the reading being wrong.

[Martin72]

After testing it for a while, here is my preliminary conclusion on the ST42.
+ Very narrow construction factor
+ Very fast measuring speed, the fastest I have experienced to date.
+ Still accurate, within its own tolerance
+Outstanding display, nothing can beat OLED
+L measurements included, many measuring tweezers only offer R and C.
+Additional parameter displays
+Dedicated ESR mode
+DC resistance mode
+open/short calibration option as with the "large" lcr meters
+Excellent operation with a single element, the multi-way joystick.
Virtually blind operation after a short familiarization period.
+Display: right/left-handed mode
+Overall a well thought-out concept
+Excellent: 4-wire design up to the measuring tips
+Firmware update option
+Very good support, continuous updates
+Excellent price/performance ratio

O Design-related mechanical restriction with regard to the components to be measured
O Battery operation: Unclear situation regarding the battery used, is it replaceable, is it a regular type available everywhere?
O Measuring frequency maximum 10kHz, no disadvantage, because it shows that the developer is aware that higher frequencies entail other circuit requirements that could not be met due to the design, other suppliers could take an example from this.

- Housing processing in the display area
- No local distributors, only available via Aliexpress

I was attracted to these measuring tweezers because so many people were so enthusiastic about them.
I tend to be skeptical about such praise, but I was pleasantly surprised.
The measuring speed is breathtakingly fast, the accuracy is good considering the design, although not outstanding, and the OLED display does an excellent job.
For the money an excellent device which has now rendered my Mastech LCR measuring tweezers out of work, the ST42 is simply outstanding in comparison.
For me, however, the ST42 is not a complete replacement for all LCR measurement tasks, as the measurement voltages/frequencies/currents are too low and the tolerances in terms of accuracy are too high.
But I think it would be perfectly adequate for 80...85% of all users and makes a further investment superfluous.
Especially if Shannon would take up my idea regarding adapters for larger measuring objects and offer a purchasable alternative.
Anyone who has been considering a DER DE-5000 should take a closer look at the ST42.
My personal LCR Meter ranking:
-ET35
-ST2830
-ET45
-ST42
-ET44
-DE5000

Summary: Good ! 

Martin

[KungFuJosh]

I agree with almost all of that, but there's no way I would believe the ET35 is superior to the ST2830. The nightmares you discussed alone are too much. Also, I had no trouble connecting to my ST2832 via Serial to USB adapter for SCPI and remote control.

The ET35 having an ethernet port doesn't make it better, especially since it barely works. 😉

ET definitely tries to be better at support than TongHui though, I'll give them that. ET tries, but fails while TH refuses to even pretend to care. That's where ST is superior, since they eventually force TH to provide updates and such.

...and that's ignoring that ET put the BNCs on backwards. 😉😉😉

[Sparrow]

Thank you Martin72 for your evaluation and comparison of these tweezers.

For my very occasional hobbyist needs, I still think the MS8911 is adequate for ME.
I do like the idea of them though.
I nearly bought the Shannon but Aliexpress kept cancelling my order and I didn't have the luck the other person had of it ever going through.

There appears to be a new LCR Tweezers on Aliexpress now.
I'm sure that they are not in the same league but are much cheaper if that's a concern for people.
It would be interesting to hear your thoughts on these:
"FNIRSI LCR-ST1 Mini Smart Tweezer LCR SMD ESR Tester Resistance Capacitance Inductance Continuity Diode Test Measurement Tools"
https://www.aliexpress.com/item/1005007481162384.html

[Martin72]

@Josh
I know both of them.
And the software is sometimes crap for sure, but it's not the only thing that matters.
We can clarify more in the appropriate thread when I'm ready for a conclusion there (will take a while).
@Sparrow:
I had actually considered having the Fnirsi compete against the ST42, despite the clear deficits on paper (datasheet).
What I don't like about both is that they have a rechargeable battery and not an easily replaceable battery like the MS8911.
I will be offering my MS8911 soon, I will keep the ST42.

[ebastler]

Of 10 resistors tested, the ST42 was able to measure 9 correctly, as was the Mastech.
Of 10 capacitors tested, the ST42 could only measure 2 correctly, the Mastech only one.
This is rather sobering when you consider that the measurement in circuits was emphasized as a point.
However, I personally did not expect anything else.

That's the main issue I have with any LCR tweezer: There are fundamental limitations to what it can measure in-circuit. So when you want to check a component in-circuit, you can never be sure (short of reverse-engineering the schematic in the relevant area) whether your results are valid or not.

I liked the form factor and the thought that had gone into the design of my ST42. Then it failed, while sitting in the drawer for a few months, and while Shannon was helpful with attempts at remote diagnosis, that went nowhere. I got frustrated and put it away (my decision, not Shannon's fault) -- and after another few months, I realise that I have not missed the ST42 much at all and have happily used my multimeters instead.

So for me, an LCR tweezer is clearly in the "nice to have" category, and I probably won't be getting another one soon. YMMV of course.

[Martin72]

I made a measurement on a transformer earlier for another thread.
This is remarkably close if you set a "large" measuring bridge like the ET35 to the same values as the ST42.
However, it also showed why measuring tweezers are a supplement for me.
Somewhat interesting:
During the measurement, the ST42 had switched itself off with a battery low warning.
However, it immediately displayed 60% when charging and was "full" after just 10 minutes.
The capacity does not seem to be the largest, which is not surprising given the design factor.

[ceut]

O Battery operation: Unclear situation regarding the battery used, is it replaceable, is it a regular type available everywhere?

When I have fixed mine (changed the CH340E), I saw the battery.
As it was glued on the "wrong" side: so I have not seen what mAh and size/reference on it.
But we have a superb(and unique) support from @Shannon  : I don't think this is a point to note 
He gaves me some piece of the PCB drawing to help me to check voltages before finding the culprit 

Also, you have done great job with checking all the LCR Meter 
For me, the ST42 is number 1  : I don't have the money or the space to have bigger LCR meter
Also, the tweezer format is really a great thing, only "problem" is as you say "Design-related mechanical restriction with regard to the components to be measured"

And for those who are interested in FNIRSI LCR-ST1: be aware of their not-finished product with firmware bugs (example DPOX180H) 

[Martin72]

I don't think this is a point to note

I think so.
The service life of a battery is foreseeable and then what?
What type is it, can you get it anywhere, can you replace it without problems...
Or will it say in 3 years sorry, this battery doesn't exist (anymore), be creative or buy something new.
I think the topic is definitely relevant.
When the button cell in my Mastech tweezers is empty, I buy a new one from the store around the corner and that's it.
It's a standard type that has been around for decades and will be around for decades.

[ceut]

I don't think this is a point to note

I think so.
The service life of a battery is foreseeable and then what?
What type is it, can you get it anywhere, can you replace it without problems...
Or will it say in 3 years sorry, this battery doesn't exist (anymore), be creative or buy something new.
I think the topic is definitely relevant.
When the button cell in my Mastech tweezers is empty, I buy a new one from the store around the corner and that's it.
It's a standard type that has been around for decades and will be around for decades.

Completely agree with you about battery powered things

I just wanted to give my feedback about the superb Shannon support, as I was having a hardware problem.
=>He helps me a lot (with PM here) to fix my ST42, with some pieces of shematics.
And when I found the problem: he send me the chip, and also the back cover - all for free (because my iron solder has slipped when I tried to remove the dead chip, and I have made a little hole inside this back cover...).
(if you want to check, was in previous page on the topic here: https://www.eevblog.com/forum/testgear/design-a-new-precision-lcr-tweezers/msg5349764/#msg5349764 )


I have not find any companies doing this.
The other serious one I have found is RD-Tech (PSU RD6006P and all great USB Meter I have), but they have not gave me the little capacitor to fix the overshoot fault I have found for free...(here if you want to check: https://www.eevblog.com/forum/testgear/ruideng-riden-rd6006-dc-power-supply/msg4354561/#msg4354561)

So, I think we have not to be worried with @Shannon support That's what I have tried to explain 

[Phil1977]

I don't think this is a point to note

I think so.
The service life of a battery is foreseeable and then what?
What type is it, can you get it anywhere, can you replace it without problems...
Or will it say in 3 years sorry, this battery doesn't exist (anymore), be creative or buy something new.
I think the topic is definitely relevant.
When the button cell in my Mastech tweezers is empty, I buy a new one from the store around the corner and that's it.
It's a standard type that has been around for decades and will be around for decades.

I´m quite sure that LiPo-pouches already are that ubiquitous that you will be able to buy most of the sizes in near future or slightly smaller ones with the same capacity.

[dazz1]

Hi
Rob of Tautech sold me a set of Shannon ST42 smd tweezers. 
Up to now I have got by with a cheap Chinese component tester, but they are hopeless for smd work.  I rarely use thru hole components these days and using multi-meter sized probes is harder than it should be.
The ST42 is definitely not bench meter accurate, but I don't need that.  It has a good display and a lot of functionality packed into a very small space. 

I designed and printed a 3D stand based on the Gridfinity storage system I have adopted.  It can now stay on the bench where it is easily accessed while being protected.
The stand holds the test board.  The case and spare parts stay in the case.

[KungFuJosh]

The ST42 is definitely not bench meter accurate, but I don't need that.

I've found it to be quite competitive even with very high-end bench meters. If you have a question about accuracy, make sure to do your open/short corrections first. Also make sure you're on the latest firmware.

See attached.

[tautech]

Hi
Rob of Tautech sold me a set of Shannon ST42 smd tweezers. 
Up to now I have got by with a cheap Chinese component tester, but they are hopeless for smd work.  I rarely use thru hole components these days and using multi-meter sized probes is harder than it should be.
The ST42 is definitely not bench meter accurate, but I don't need that.  It has a good display and a lot of functionality packed into a very small space. 

I designed and printed a 3D stand based on the Gridfinity storage system I have adopted.  It can now stay on the bench where it is easily accessed while being protected.
The stand holds the test board.  The case and spare parts stay in the case.

Dazz, pop this message into the ST42 thread and Shannon may choose to add it to a POI list.
https://www.eevblog.com/forum/testgear/design-a-new-precision-lcr-tweezers/

[KungFuJosh]

That stand is pretty awesome.

[dazz1]

The ST42 is definitely not bench meter accurate, but I don't need that.

I've found it to be quite competitive even with very high-end bench meters. If you have a question about accuracy, make sure to do your open/short corrections first. Also make sure you're on the latest firmware.

See attached.

I don't need ultra precise but your comparison shows the ST42 is more than accurate enough for my needs.  Actually quite impressive performance from such a small device.

[dazz1]

Dazz, pop this message into the ST42 thread and Shannon may choose to add it to a POI list.
https://www.eevblog.com/forum/testgear/design-a-new-precision-lcr-tweezers/

? ? ? POI list ? ? ?

[tautech]

Dazz, pop this message into the ST42 thread and Shannon may choose to add it to a POI list.
https://www.eevblog.com/forum/testgear/design-a-new-precision-lcr-tweezers/

? ? ? POI list ? ? ?

Points Of Interest.

We OP's/thread starters often grab links to posts and list them which provides a fast method to find them.
eg. scroll down to the the POI list for the SDS804X HD we played with last Saturday:
https://www.eevblog.com/forum/testgear/siglent-sds800x-hd-12-bit-dsos-coming/

[Martin72]

Thank you Shannon !