LCR tweezers 100 kHz.

[mawyatt]

From time to time I'm fixing broken car remotes. No available schematics of course, the only way to find out values - to have another key of same model and measure its components. Most important ranges - below 200nH and below 10pf (there are many components with such values in car fobs). Often they are in 0402 size which doesn't help either. So good LCR-meter with 100kHz range and stable readings is a must.

You don't need to buy tweezers with a measurement frequency of 100 kHz. If the resolution of 0.1 uH and 0.1 pF is enough, then tweezers with a measurement frequency of 10 kHz-ST1 will do just fine. As a cheaper alternative to Pro1-LCR 1S. It has 100 kHz.

You do realize that a resolution of 0.1pF @ 10KHz requires the instrument to resolve the equivalent of a change in parallel Z of 160MΩ added to or removed from the DUT Z.

Best

[iet]

I see a resolution of 0.1 pF on the ST1 display. This is easily verified with the appropriate capacitors.ranchero said in his message that he would like to measure capacitance below 10 pF. This could be 9,8.2, 4.7, 3.3, 2.2, 1.5, 1 pF or any other number. That is, he needs to measure pF units. And a resolution of 0.1 pF makes it possible to more accurately measure capacitors with tenths of a pF.

[iet]

For general information - pF table. Test board. It is not finished yet. 0.1-100 pF.

[ranchero]

You don't need to buy tweezers with a measurement frequency of 100 kHz. If the resolution of 0.1 uH and 0.1 pF is enough, then tweezers with a measurement frequency of 10 kHz-ST1 will do just fine. As a cheaper alternative to Pro1-LCR 1S. It has 100 kHz.

Sometimes there are inductors below 100nH. I need at least 10nH resolution.

[iet]

Sometimes there are inductors below 100nH. I need at least 10nH resolution.

Look at this one.
https://us.rs-online.com/product/rs-pro/1238652/71079735/?srsltid=AfmBOopYGS5zozDeYRiWmSTybav5aA94T27t9FyU2Juip0h9m5kMDOWj

[iet]

Several measurements, as mentioned in message 76. Tweezers ST1-10 kHz.

[iet]

Precision resistors 0.1% arrived. Soldered into the test board. Tweezers LCR Pro1 Plus.

[iet]

Precision resistors 0.1%.

[iet]

Precision resistor 0.05%.

[iet]

Making a test board for testing leaded electrolytic and other types of capacitors took more time than other test boards.
There are two sockets on the board. One is taken from an industrial board, the other is a well-known Zif socket. It turned out to be a very multifunctional and convenient thing.
You can test capacitors with different lead thicknesses.
You can test capacitors with different lead lengths.
You can test capacitors with different distances between leads. The maximum distance is 40 mm.
Good and reliable contact. The resistance between any contacts and test pins is 10 mOhms. That is, we will always subtract this value from the measurement result.
The test pins are silver-plated, which ensures high-quality contact. They are well suited for all types of tips of different tweezers, ordinary multimeter probes and Kelvin clamps. If the pins wear out, they can be easily replaced.
You can take measurements with two devices at the same time.
The board has a connector for connecting a device for forming capacitors.
It is also possible to measure leaded resistors.

[iet]

For example, I measured the ESR of a 3900 uF capacitor, Low impedance series.
18-10 = 8 mOhms.
Now I can calmly start measuring the parameters of the capacitors and carefully place them in the appropriate box.

[iet]

There are no problems with electrolytic capacitors. There are many of them and the results will need to be entered into a table. Moreover, it is better to group them by manufacturers. At the same time, separate regular and low-impedance capacitors. But with picofarad capacitors 0.1-1 pF it is more difficult. While I am waiting for the ordered 0.1 pF, I found another one for 0.47 pF. I measured with two tweezers. The obtained values ​​coincide and correspond to the accuracy and resolution of these tweezers. This is good.

[iet]

Low impedance electrolytic capacitors of different series. Nippon Chemi-Con. Measured ESR with two tweezers. Pro1 Plus-100 kHz and ST1-10 kHz.
ESR table.

[iet]

While browsing the internet for information about the QPLINK 1S tweezers, I found a link to a review of these tweezers. It is easy to read using Google Translate.
There are tables of L, C, R measurement results with three devices.
Of what interests me, there is a measurement of 10 nH inductance. There are calibrations. There is no information on resistors in the milliohm range and on measuring the ESR of capacitors at a frequency of 100 kHz.
Overall, the review is positive.
But I haven't decided yet whether to order it or not to replace the MS8911 or FNIRSI ST1.
Conclusions from the review.
Conclusions
Very good tweezers, surprisingly accurately measure capacitances at a frequency of 1 kHz up to 100 uF. At 10-100 kHz the error is greater, but these are still operating modes. And these tweezers are definitely better than Fnirsi lcr st1.
Pros:
Resistances from 100 mOhm with a resolution of 1 mOhm
Accurately measures resistance, accurately measures capacitance and inductance at a frequency of 1 kHz
Calibration capability
Measures voltage normally and accurately after calibration
There is a calibration board for self-assembly, there is a screwdriver for disassembly
Good battery capacity and adequate power consumption
Clear display with wide viewing angles
Adequate and fast display rotation for right and left hand
Fast dialing in 10-100Khz mode
Cons:
Calibration is required to fully utilize the device's potential.
Only resistors are soldered on the calibration board.
The resistors on the calibration board need to be replaced.
There is some instability of readings in the measurement mode due to temperature, frequency drift and ADC noise, however, this has little effect on accuracy.
Diodes are tested only up to 1V
https://mysku.club/blog/aliexpress/102487.html
In the meantime, I am preparing to measure the ESR of capacitors at a frequency of 100 kHz.
Finished a desktop ESR tweezers for 100 kHz with a large microammeter, 140x70 mm. Between tens of uA, ten divisions. Excellent sensitivity, good overview. Linear scale 1-500 mOhms.
I already gave a link to the diagram in message 60. The board is from the first version of the tweezers. But for the first time I used Schottky diodes with Vf-0.1 v.
Most of the time was spent on linearizing the scale, so I had to select some resistors. Highly stabilized power supply 3.7 v.
Now the T2 tweezers with this scale will take part in measurements at a frequency of 100 kHz on a par with digital tweezers.

[iet]

Measuring ESR of electrolytic capacitors at 100 kHz.

[iet]

Measuring ESR of electrolytic capacitors at 100 kHz.