New LCR meters, Zoyi ZT-DQ01 and ZT-DQ02 (March 2025)

[BillyO]

Did anyone measure the thickness of the 3 "blades" of the Ziboo kelvin clips?

Mine measure at 1.0 mm.

[Constant Cluelessness]

My meter has arrived but I feel that it may be faulty.
When I try and measure resistors, the value climbs for a long time and when I try to measure capacitors the value falls for a long time. From videos I have seen it shouldn’t be doing this but instead should oscillate above and below the value until it settles. Also, I cannot do a short calibration with the 2 wire leads they sent.
(I do not have kelvin clips for the LCR portion of the meter as the mistakenly did not send them, so I have been unable to test if they calibrate).

Linked are videos showing the 2-wire leads failing short calibration and components plugged into the slot terminals: a 75Ω resistor, a 68nF capacitor, a 220uF solid electrolytic capacitor and a 470uF electrolytic capacitor. Notice how the resistor increases in value over time for a very long time (though the rate of increase gets slower) and for the capacitors they decrease in value over time.
From what I have seen on people’s video reviews of the meter, this should not happen and instead the value should oscillate above and below the value of the component as it homes in.

The meter is on firmware 1.1.2

Is this normal behaviour or should I return it for a replacement? Certainly the leads not calibrating is not ideal. If someone could test and compare with their own meter it would be interesting to see if it responds in the same way to similar value components. All the settings for each component are shown in the corresponding videos

2 wire calibration failure: https://pixeldrain.com/u/yU7DFHLd
75 ohm resistor: https://pixeldrain.com/u/ssLAdBJB
68nF cap: https://pixeldrain.com/u/P7Poy2kY
220μF solid electrolytic cap: https://pixeldrain.com/u/JsbQBFgP
470μF electrolytic cap: https://pixeldrain.com/u/ifM6HF9g

If anyone has a problem viewing the videos, let me know and I will try to find a different place to upload them.
Thank you!

[indman]

Is this normal behaviour or should I return it for a replacement? Certainly the leads not calibrating is not ideal. If someone could test and compare with their own meter it would be interesting to see if it responds in the same way to similar value components. All the settings for each component are shown in the corresponding videos

My advice is to reset the settings to factory defaults and don't perform any further calibrations. Re-test the same parts and provide photos of the specific parts you are testing.

[BillyO]

So, I have noticed what you are seeing with most of my LCR meters and where it seems to come from is the handling of the component.  If I pick up the component by the body and insert it into a fixture, then I see exactly what you see.  Resistors going up in value, capacitors going down, for a couple of minutes, then finally stabilizing  If I pick up the component by the leads (or tweezers for SMD), not heating the body of the component with my fingers, I get a stable reading right away.

I just measured a 50uf cap.  When I picked it up by the leads, it read 64.400 uF right away and stayed there (varying +/- 0.001).  Taking it out by holding the body, keeping between my fingers for 10 seconds, then re-inserting it, it initially measured 64.559 uF then over 5 minutes returned to 64.400 uF.

If you need a quick reading, do not hold your components by their body before inserting them.  Otherwise, if this is not possible, give them 5-10 minutes in the fixture for the temperature to stabilise before recording the reading.

[indman]

Yes, the temperature dependence of the readings on the ZT-DQ02 will be more noticeable because the resolution is 80,000 counts on many ranges.
On my DE-5000, the temperature dependence of the readings is also present, but it is much less pronounced.

[mawyatt]

My meter has arrived but I feel that it may be faulty.
When I try and measure resistors, the value climbs for a long time and when I try to measure capacitors the value falls for a long time. From videos I have seen it shouldn’t be doing this but instead should oscillate above and below the value until it settles. Also, I cannot do a short calibration with the 2 wire leads they sent.
(I do not have kelvin clips for the LCR portion of the meter as the mistakenly did not send them, so I have been unable to test if they calibrate).

Linked are videos showing the 2-wire leads failing short calibration and components plugged into the slot terminals: a 75Ω resistor, a 68nF capacitor, a 220uF solid electrolytic capacitor and a 470uF electrolytic capacitor. Notice how the resistor increases in value over time for a very long time (though the rate of increase gets slower) and for the capacitors they decrease in value over time.
From what I have seen on people’s video reviews of the meter, this should not happen and instead the value should oscillate above and below the value of the component as it homes in.

The meter is on firmware 1.1.2

Is this normal behaviour or should I return it for a replacement? Certainly the leads not calibrating is not ideal. If someone could test and compare with their own meter it would be interesting to see if it responds in the same way to similar value components. All the settings for each component are shown in the corresponding videos

2 wire calibration failure: https://pixeldrain.com/u/yU7DFHLd
75 ohm resistor: https://pixeldrain.com/u/ssLAdBJB
68nF cap: https://pixeldrain.com/u/P7Poy2kY
220μF solid electrolytic cap: https://pixeldrain.com/u/JsbQBFgP
470μF electrolytic cap: https://pixeldrain.com/u/ifM6HF9g

If anyone has a problem viewing the videos, let me know and I will try to find a different place to upload them.
Thank you!

If you want to validate your LCR meter on certain ranges you need good reference components with known values. These known reference values can be established with a Lab Bench type LCR for example using typical available quality components (low TC is a benefit), or with proper designated reference components.

For low value capacitors (<10nF), Mica types (we've found molded is preferred over dipped) are a good choice, and can usually be found with 1~2% tolerance. For resistors good low TC and highly accurate (0.01%) metal film/bulk are readily available.

Best

[trobbins]

What custom connection jig would suit measuring a capacitance standard such as a GR 1404A 1nF ?  My standard has GR 874 terminals, but likely a similar jig layout for BNC terminals. 

Would the jig take the Hcur and Hpot leads separately (but in a screened cable) through to the DUT cap H terminal, and similarly L leads through to the DUT cap L terminal, and connect the guard to the cable shields going to each DUT terminal (and hence to the DUT enclosure for the cap L terminal) but not otherwise to the DUT enclosure?  A typical shielded coax cable to a GR 874 or BNC terminal would just be single wire (not two wire), so the cur and pot node would then be back near the meter terminals, rather than out at the DUT cap terminals.

And then the query is also how to make a short and open set of tests.

[BillyO]

Do you have access to one?

Used they go for $1500, new more like $7500.

It would be excellent to borrow one for something like this but, even used they are more than 15 times the cost of this meter.

[trobbins]

Yes, I have a 1nF.

[mawyatt]

@ trobbins,

The issue is not with the cap reference but getting the proper connections to/from the reference in a stable and repeatable manner to the lab grade bench LCR meter. We often taped the cables to the bench when doing precision VNA measurements way back, and these cables were/are expensive.

Your references are better than anything we have, but using Kelvin cables likely the best approach with a set of quality Kelvin Cables/Clips like the TH26011CS. Keeping them physically stable likely will require taping to the work bench and such. This is something we discovered with our less-than-reference-grade caps, the difficulty in getting precise repeatable results from day to day.

All this got us thinking that the issue is the connections to/from the reference and why not remove this uncertainty like using the special LCR meter fixtures that directly connect electrically and mechanically to the 4 LCR meter BNC connectors. We had already used modified and developed custom direct connect fixtures for SMD devices which had shown excellent repeatability, the modified fixture is for higher Z SMD DUT and the custom for low Z SMD DUT, where the DUT end terminals make the 4 wire Kelvin connections.

We placed our best caps in a direct connect fixture and this has proved to be quite good for our needs. The old Soviet Micas are excellent examples of our attempts to move closer to your superb GR references!! We even included a temp sensor mounted to the Soviet metal can. This direct connect fixture allows the reference cap to be within a stable mechanical and electrical environment, and allows simple direct Open Short Calibration with similar type setup fixtures, improving these setup calibrations.

Anyway, don't want to distract anymore, if interested we can discuss more details.

Best

[BillyO]

I don't think the TH26011CS will fit his Zoyi.

Maybe something like this: