Products > Test Equipment
LCR Tweezers test and analysis (HP-990, DT71, ST5S...)
<< < (9/13) > >>
2N3055:

--- Quote from: Shannon on February 15, 2021, 03:37:29 pm ---I try to explain why do these tweezers cannot support milliohm resistance.

Because they said they cannot support in the datasheet.    :palm:

ST5S has an offset spec, For the resistance ≤ 25mΩ
LCR Pro1 has a similar spec, looks like the offset is ≤ 20mΩ

--- End quote ---
With LCR Pro1  you can calibrate it out, to few miliohms...
Problem is, as I said, that tiny pointed tweezer tips cannot have low enough contact resistance to have repeatable measurements...
As you vary pressure, resistance changes in front of your eyes.. It can measure it just fine.
For larger trough hole components, if you make contact with wider flat part of tweezers, you get better results.
Also you need to clean tips with alcohol occasionally, it's gold plated and it wont corrode but it will get dirty.. 
tautech:

--- Quote from: Electro Fan on February 15, 2021, 07:00:03 pm ---Maybe there is an opportunity for an EEV branded tweezer.

--- End quote ---
Only if Dave has changed his ideas about SMD tweezers.
When he reviewed the ST3 years back he didn't think much of them yet many of us have been using them for years.
Shannon:

--- Quote from: tautech on February 15, 2021, 07:36:35 pm ---
--- Quote from: Electro Fan on February 15, 2021, 07:00:03 pm ---Maybe there is an opportunity for an EEV branded tweezer.

--- End quote ---
Only if Dave has changed his ideas about SMD tweezers.
When he reviewed the ST3 years back he didn't think much of them yet many of us have been using them for years.

--- End quote ---
haha
I watched Dave's ST3 video again, and he was so funny  "I love Canadians!" :-DD

In fact, My friends and I have discussed this topic, and we think that a more cost-effective tweezer with similar performance may be possible now
Shannon:

--- Quote from: 2N3055 on February 15, 2021, 07:03:51 pm ---
--- Quote from: Shannon on February 15, 2021, 03:37:29 pm ---I try to explain why do these tweezers cannot support milliohm resistance.

Because they said they cannot support in the datasheet.    :palm:

ST5S has an offset spec, For the resistance ≤ 25mΩ
LCR Pro1 has a similar spec, looks like the offset is ≤ 20mΩ

--- End quote ---
With LCR Pro1  you can calibrate it out, to few miliohms...
Problem is, as I said, that tiny pointed tweezer tips cannot have low enough contact resistance to have repeatable measurements...
As you vary pressure, resistance changes in front of your eyes.. It can measure it just fine.
For larger trough hole components, if you make contact with wider flat part of tweezers, you get better results.
Also you need to clean tips with alcohol occasionally, it's gold plated and it wont corrode but it will get dirty..

--- End quote ---

Yes, I agree with you. I've also thought about this issue.
Is it possible to make tweezers tip into a pen tip like structure? Each tweezer tip is composed of two metal tips. It's cool to think of. 8) as attached.

Another problem is that for the LCR meter, the measurement of milliohm level is limited by the amplitude of the excitation signal, it is not easy to measure, as bateau020 said

Suppose the exciting current is 1mA, the resistance is 1mOhm, and the voltage amplitude is only 1uv
Electro Fan:
Nice illustration Shannon 👍
Navigation
Message Index
Next page
Previous page
There was an error while thanking
Thanking...

Go to full version
Powered by SMFPacks Advanced Attachments Uploader Mod