Smart SMD tester MS8911.

[iet]

Maximum capacitance value that tweezers can measure is 22 mF.
Measurement with a multimeter with a limit value of 100 mF.
33 mF.
55 mF.

[iet]

Inductance 0.1 uH was measured with two tweezers with the same result.
Now let's check the secondary parameter Rs when measuring inductance with tweezers LCR ST1. More accurate tweezers LCR Pro1 Plus.

[iet]

Resistors.
Minimum value - 0.1 mOhms.
First, it is necessary to perform a good zeroing of the readings with the tweezers probes closed. The upper part of the button from the old equipment was chosen as a device. The tips fit very tightly inside and provide a very reliable high-quality contact.
In this position, the tweezers were tested for 1 hour to understand what kind of drift it had. Within half an hour, the drift was 0.2 mOhms. At the end of the tests, it increased to 0.3 mOhms.
After a short break due to battery charging, I continued to study the drift of the tweezers in the milliohm range.
In the closed probe mode, the tweezers worked for 4 hours until the battery was completely discharged. Working for 3 hours with a green glow of the battery charge indicator, the drift did not change.And the most interesting thing is that with a red glow of the battery charge indicator, this drift remained at the same level until the battery was completely discharged.
In addition to studying the drift of the tweezers, my device for the zeroing mode of readings has proven its high reliability.
Resistor 1%.

[iet]

I have good news. My tweezers have new tips. The problem with good tips has always been. They are all of different design, have their own coating of different metals. But whatever the design features, they must be thin enough at the tips. The area of ​​contact with the component is very small, so over time the coating wears off. This leads to deterioration of contact and introduces some error in measurement. This is most noticeable in the mOhms and pF range. My tips are made of polished brass plates 1 mm thick. Excellent contact and rigidity. Easy to process. The contact area has increased slightly. Durable, wear-resistant. Always maintain high quality contact.
I conducted an experiment on the drift of tweezers with short-circuited probes. I repeated the experiment on a 5 mOhms 1% resistor. The clamping force was fixed. Over the course of 1 hour, the drift was +/- 0.2 mOhms.

[MiniCheck]

I have good news. My tweezers have new tips.

Where did you get these tips from?

[iet]

Where did you get these tips from?

I made them myself. I had to work a little with different tools.

[iet]

On the FNIRSI website firmware V1.5.
https://www.fnirsi.com/pages/download-firmware

[iet]

Resistors 1,1.5,2 mOhms 1%.

[iet]

In the FNIRSI LCR-ST1 thread on the Chinese forum there is very interesting information about the changes that were made to different firmware versions V2,3,4,5.
LCR-ST1-V1.5-20240827
1. Repair the logic of automatic shutdown setting
2. Add the function of identifying the direction of diode

LCR-ST1-V1.4-20240803
1. Repair the abnormal progress of resistance measurement in some intervals

LCR-ST1-V1.3-20240725
1. Repair some problems of diodes

LCR-ST1-V1.2-20240714
1. Add the function of measuring on and off under diode
2. Add Z and X secondary parameters
3. Add data saving
http://www.crystalradio.cn/thread-2149620-4-2.html

[iet]

After measuring the resistors, I measured the esr of a polymer capacitor from Panasonic SP-Cap, GY 820 uF, 2v. ESR<3 mOhms.
https://api.pim.na.industrial.panasonic.com/file_stream/main/fileversion/8713

[iet]

I made another pair of tips from polished brass. The thickness is the same as the original probes - 1.5 mm. They fully correspond to the dimensions and profile of the original probes. In addition, bolts were used to attach the tips. This completely eliminated the slightest displacement of the tips. They are practically eternal, there is nothing to wear out there.

[DaneLaw]

I made another pair of tips from polished brass. The thickness is the same as the original probes - 1.5 mm. They fully correspond to the dimensions and profile of the original probes. In addition, bolts were used to attach the tips. This completely eliminated the slightest displacement of the tips. They are practically eternal, there is nothing to wear out there.

What's your take on the curved tweezers.?
One of the benefits of the Fnirsi variant ST1 is that it also comes with curved/hooked tweezers.

The Zoyi MD1 also comes with an extra spare set for an added cost of +0.15cent, but it looks identical to the main.

[iet]

What's your take on the curved tweezers.?

It's great that FNIRSI gives them away. Sometimes it's necessary. Although the main work is straight tips.
I must say that the original tips will be used in the same way as the brass ones. They have notches and this has its practical application. It turns out that I will be working with three pairs of tips.

[DaneLaw]

What's your take on the curved tweezers.?

It's great that FNIRSI gives them away. Sometimes it's necessary. Although the main work is straight tips.
I must say that the original tips will be used in the same way as the brass ones. They have notches and this has its practical application. It turns out that I will be working with three pairs of tips.

They aint free as per se, but an incl. addon on the ST1bundle that comes with the ST1-form-fitted casing.
Its around 2 to 3€ difference for the added angle tweezertips & bag.
You went for the bag-bundle or just the tool.?

Nowadays, it only looks like its the bag-bundle that is on offer, though 3 weeks back when I purchased one, you could select-
Only the Zoyi MD1 has arrived, which has impressed me sofar (with the price in mind)

[MiniCheck]

With this capacitor, RNS1C470MDS1 (47 uF, 16V), I get the following approximate readings with the Fnirsi LCR-ST1:

@100 Hz, 580 mOhms, 51 uF
@1 KHz, 73 mOhms, 50 uF
@10 KHz, 17 mOhms, 52 uF (the ESR reading does jump a bit)

The datasheet shows the ESR as 42 mOhms.

Here's the interesting thing: the Fnirsi LCR-P1 shows a sold 50 mOhms for the ESR and 55 uF for the capacitance.

The capacitor is brand new and both measuring devices have the latest firmware.

[4thDoctorWhoFan]

The datasheet shows the ESR as 42 mOhms.

At what frequency?

Here's the interesting thing: the Finirsi LCR-P1 shows a sold 50 mOhms for the ESR and 55 uF for the capacitance.

Again, at what frequency?

The ESR will vary considerably depending on the frequency.

[MiniCheck]

The 42 mOhms is at 100 KHz, 20 degrees C.

I don't know what frequency the Fnirsi LCR-P1 uses.

The data sheet is here for the capacitor: https://www.nichicon.co.jp/english/series_items/catalog_pdf/e-rns.pdf

[indman]

The capacitor is brand new and both measuring devices have the latest firmware.

It's hard to call these toys measuring devices.  Do you have more serious instruments to evaluate the quality of the capacitor
RNS1C470MDS1?

[Paul T]

The Zoyi MD1 also comes with an extra spare set for an added cost of +0.15cent, but it looks identical to the main.

I can confirm this.  Wishing for a serrated set which can hold onto loose piece SMD's.

[MiniCheck]

It's hard to call these toys measuring devices.  Do you have more serious instruments to evaluate the quality of the capacitor
RNS1C470MDS1?

  

No, I'm afraid not. I think they're ok for my needs.

[iet]

You went for the bag-bundle or just the tool.?

I ordered bag-bundle.
In-circuit measurement of resistors with new brass probes.

[iet]

This is what I wrote about. The gold coating of the tips has worn off after 9 months of intensive use in the areas of greatest contact.

[iet]

Measuring 0.1% resistors.ST1.
100R 0.1%     R:100.0             
100k 0.1%     R:100.0   
1M 0.1%        R:1.00   
On the Chinese forum, which has already been linked, there is a topic about a simple LCR meter. The design of a conventional meter gradually acquired the shape of tweezers. In my opinion, this is the first attempt to simultaneously display the maximum number of parameters of the measured component on the display. 6 parameters, plus frequency and range. The accuracy was quite good, especially surprised by the large-sized probes, even more rigid than my tweezers. The developer's idea is clear - to convert a desktop LCR meter into the shape of tweezers. A very interesting and promising thing, which can be considered a new qualitative stage in the design of LCR tweezers.
http://www.crystalradio.cn/thread-2150171-11-1.html

[iet]

I made a more advanced device for zeroing. At the same time, it can be used as a stand for tweezers.

[iet]

I measured the maximum resistance that I had -50 MOhm. Although in the technical specifications it is 10 MOhm. The value is displayed by the secondary parameter Rs. By the way, the Chinese tweezers in the photo have 100 MOhm.