LCR Cal Test PCB

[mawyatt]

For these low value capacitors we are more concerned with the Capacitance C than Q and with the overall impedance Z.

Best,

[KungFuJosh]

For these low value capacitors we are more concerned with the Capacitance C than Q and with the overall impedance Z.

So at what point do you start caring about Q?

[mawyatt]

We generally don't, for us "Q" is just a qualitative term like High Q or Low Q, similar to "Low Loss".

For example the mentioned High "Q" C0G type capacitors, here we are interested in the capacitance but knowing it's "Low Loss" because of High "Q", meaning Rs is low compared to Z.

Best,

[KungFuJosh]

We generally don't, for us "Q" is just a qualitative term like High Q or Low Q, similar to "Low Loss".

For example the mentioned High "Q" C0G type capacitors, here we are interested in the capacitance but knowing it's "Low Loss" because of High "Q", meaning Rs is low compared to Z.

Perfect, now I just need to remember that. 😉

[Martin72]

Q is not entirely uninteresting.
Chokes, for example, which have the same induction value at first glance, but differ significantly in terms of Q, will subsequently cause problems in terms of losses/function.
The same also largely applies to capacitors.
What is interesting in this context is how precisely the meters display or calculate and indicate this value.

[Kean]

Did the Gerber files for V5 get shared?

I'd like to make one of these up at some point to see how my CKT5000 compares with my handheld Tonghui and ST42 tweezers.  And whatever I buy next...  .

[KungFuJosh]

Did the Gerber files for V5 get shared?

I'd like to make one of these up at some point to see how my CKT5000 compares with my handheld Tonghui and ST42 tweezers.  And whatever I buy next...  .

Not yet. I'm waiting on updating the BOM and stuff. For now I have extra (unpopulated) PCBs I can sell for $10 plus shipping if anybody wants them.

[Kean]

Thanks Josh.  I can wait.  Just wanted to be sure I didn't miss a mention of it.
I haven't ordered the parts yet, and shipping a single PCB to me down under makes little sense.

[mawyatt]

Here's something folks might find interesting wrt to DMM testing/calibration and forgoes the Kelvin Clips.

https://www.eevblog.com/forum/testgear/ac-rms-dmm-tests/msg3940957/#msg3940957

We may have posted something on the Resistive & Capacitive devices but can't remember since long ago

Obviously these are specific to Bench type DMM use with the 4 terminals (except the Capacitor set which is just 2 terminal).

Best,

[KungFuJosh]

I got the Hioki 3532-50 working, and ran it through the Cal Test PCB.

Looks decent, but could definitely use a calibration/adjustment from Hioki. PDF attached.

[shabaz]

Nice instrument. I've not used a Hioki LCR meter.
I had a quick look at the PDF, the results look like it's functioning well. Unless I missed something, aside from the very large inductances at high frequency, which might not be very relevant, all remainder measurements looks very close to the comparison measurements, at least so close that any circuit designed for normal tolerances should function extremely well if components are selected based on measurements from the Hioki.

[KungFuJosh]

Nice instrument. I've not used a Hioki LCR meter.
I had a quick look at the PDF, the results look like it's functioning well. Unless I missed something, aside from the very large inductances at high frequency, which might not be very relevant, all remainder measurements looks very close to the comparison measurements, at least so close that any circuit designed for normal tolerances should function extremely well if components are selected based on measurements from the Hioki.

Thanks, I'm a big fun of Hioki LCRs. The quality is unmatched so far from what I've used.

There are two Hiokis on there (of mine, and the 3rd one is Mike's) all are really nice.

Regarding the 3532-50, for the most part it agrees pretty well. However, there are a few things that are too far off.

For example, 1M and 10M resistance measurements are generally bad. 100k is also too far out to be acceptable, though not nearly as bad. 10kΩ and below generally seem close enough.

Step dissipation factor is not good enough either, especially in the smaller values.

Capacitance is generally pretty good except for 10pF at 10kHz and below. Granted, that's not really expected to do very well, but was father off than the other meters.

Inductance in general is pretty good except for 100nH is way off. However, I don't think those inductors were anywhere near where they should have been for specified test frequencies. That said, it was still farther off than any of the other meters. I have new caps and inductors to try out on a new board now that all these meters have been compared.

Still generally pretty darn good for a 23 year old LCR meter. Hioki does adjustments with no extra charge when they do calibrations for Hioki gear, so I'm waiting to hear back from them for pricing.

Thanks,
Josh

[shabaz]

I've got an ancient LCR meter that I need to work on, (it's been on the back-burner for a couple of years!) it runs, but there's a higher discrepancy than desired, compared to a more modern LCR meter.
It's a 'Chen Hwa 1061 LCZ meter'. It was low-cost so I took a gamble. When I took a look inside, it was pretty old.. running with a Zilog Z80.

[KungFuJosh]

Chen Hwa 1061 LCZ meter

That's an old school beast! The picture I found made it look kinda huge. It should be a fun project though when you finally have time.

[shabaz]

Definitely. I'll take some pics and share them next time I have it open.

[KungFuJosh]

Here's the Gerbers and BOM for the LCR Cal Test V5 PCB.

Note: This is being shared for home & hobby use. Commercial use or reproduction is not approved. Use at your own risk; I take no responsibility for anything.

There are details in the PDF version of the BOM. For example, I used different caps for the 1nF whether testing capacitance or step D factor. The cap listed for step D factor had values in the range needed to be close to the nominal targets.

Also note that there are 2 inductors listed for 100µH. The one marked NRND is easier for most people to measure if they don't have an LCR that supports higher frequencies. I guess grab them while they last. 😉

Thanks,
Josh

PS. If anybody in the US would like, I do have a few unpopulated PCBs available for $10 each plus shipping. Send me a PM if interested.

[Martin72]

That reminds me that I should finish assembling my circuit board.

[KungFuJosh]

You might want to get at least the replacement inductors from the updated BOM.

I improved the 1nF and lower cap choices too, but the previous ones were probably fine.

Unrelated side note: Mouser sent me the wrong inductors for the 100nH range. They were 100µH instead of 100nH. I'm waiting on replacements for those, but the rest were great. I'll eventually posts some measurements when I'm done screwing around with other things. 😉

[KungFuJosh]

Mouser sent me the wrong value for 100nH, but surprisingly, the 805 chip book I bought had some 10nH and 100nH I didn't have any trouble testing. 🤷

Here they are in the SMT test fixture. I have to redo the kelvin tests with the cable correction done. Oops.

[KungFuJosh]

Here they are with the test PCB. These values are very sensitive with the kelvin clips.

[Martin72]

I got the Hioki 3532-50 working, and ran it through the Cal Test PCB.
Looks decent, but could definitely use a calibration/adjustment from Hioki. PDF attached.

Especially in the resistance range, it looks as if something high-impedance is lying parallel in the measuring path.
Possibly check the front end.

[mawyatt]

Here they are with the test PCB. These values are very sensitive with the kelvin clips.

Try using Low Z ON if possible, unless worried about DUT damage with high current. This provides more DUT current with low Z components and thus creates a higher measurement voltage which improves measurements

You need to do a Cal with it ON as well.

BTW think your previous post should be 100nH and 10nH, not nF!!

Best,

[KungFuJosh]

Try using Low Z ON if possible, unless worried about DUT damage with high current. This provides more DUT current with low Z components and thus creates a higher measurement voltage which improves measurements

You need to do a Cal with it ON as well.

I will give that a try, thank you.

BTW think your previous post should be 100nH and 10nH, not nF!!

I switch those around so frequently it's ridiculous. I usually catch them and edit before anybody notices though. 😉

Especially in the resistance range, it looks as if something high-impedance is lying parallel in the measuring path.
Possibly check the front end.

Interesting point. I'm not in a rush to open it back up, but I'll probably need to check that out. I didn't see anything astray when I cleaned it (gently) before closing it up. If only I could get a schematic for it. 🙄

ETA: I thought about it more, and that doesn't make sense to me. Every measurement range is separated by resistance level. 1M and 10MΩ are separate levels (you can hear the relays click as it switches through the different ranges from .1Ω to 100MΩ), and I can't think of any single thing in the front end that would throw them both off by ~50%. If a 10M resistor found its way there, that would make sense in the 10M range, but the 1M range shouldn't drop lower than 90%.

Is there anything besides needing adjustment that would set two separate ranges apart? Or maybe the resistance ranges are in series? If that's the case, then there would need to be something around the 1MΩ position to throw off only the higher ranges. I should test the 100MΩ range and see what that looks like. I still don't know what could throw both ranges off by ~50%.

My hope is that those ranges only need adjustment. What do you think?

Thanks,
Josh

[mawyatt]

Could this be the Cal values got messed up for the Resistance Ranges?

Best,

[KungFuJosh]

Could this be the Cal values got messed up for the Resistance Ranges?

That's my theory. 100k is slightly off, and 1M and 100M are at 50%. I don't know what would have messed them up. The device is 23 years old, it's time for an adjustment. If I can figure out how. 😉