Author Topic: Anti-static material - resistance  (Read 1344 times)

0 Members and 1 Guest are viewing this topic.

Offline TomS_Topic starter

  • Frequent Contributor
  • **
  • Posts: 848
  • Country: gb
Anti-static material - resistance
« on: March 05, 2019, 12:33:26 pm »
I bought an IC lead straightener tool off Amazon. The instructions on the box say it has a lug for attaching a ground strap.

Out of sheer curiosity I decided to measure it with a multimeter set to resistance, as the plastic had a texture which was unlike other anti-static plastics I have seen, and got no reading.

Im not a massive expert at this kind of thing, but I'd expect it to be slightly conductive and give a reading?
 

Offline threephase

  • Regular Contributor
  • *
  • Posts: 205
  • Country: gb
Re: Anti-static material - resistance
« Reply #1 on: March 05, 2019, 02:55:17 pm »
Yes it should have, but it could well be in the GOhms range and a standard multimeter may not be able to read it.

Even if I test my anti-static work mat, my multimeter, a Keysight U1461, goes OL on resistance range, if I switch to to 50V insulation test, I get circa 10 GOhms.

Kind regards.
 
The following users thanked this post: TomS_

Offline exe

  • Supporter
  • ****
  • Posts: 2604
  • Country: nl
  • self-educated hobbyist
Re: Anti-static material - resistance
« Reply #2 on: March 05, 2019, 02:58:16 pm »
Dave did a review of his esd mat. The upper part was unconductive.
 
The following users thanked this post: TomS_

Offline Zenith

  • Frequent Contributor
  • **
  • Posts: 508
  • Country: england
Re: Anti-static material - resistance
« Reply #3 on: March 05, 2019, 04:41:46 pm »
I Googled " IC lead straightener tool off Amazon" and the only one I found looks like the one I've got.

With a DMM with a 20MegOhm range, with one probe on the earth screw and another on the same piece of plastic a few millimetres away, it shows about 1 MegOhm. On the central piece of plastic with the probes a few mm apart, it shows about 5 MegOhm. On the other side piece of plastic I sometimes see a reading with both probe tips dug in.

It only needs to be slightly conductive to dissipate static and that may easily be missed with a normal DMM.

« Last Edit: March 05, 2019, 04:43:54 pm by Zenith »
 
The following users thanked this post: TomS_

Offline DaJMasta

  • Super Contributor
  • ***
  • Posts: 2336
  • Country: us
    • medpants.com
Re: Anti-static material - resistance
« Reply #4 on: March 05, 2019, 05:56:30 pm »
To properly analyzer antistatic material, you really need an insulation resistance meter or similar, something that can read out at least hundreds of MOhm - the input impedance of a regular multimeter is just too low for that most of the time, so you can't get a reading.  Same goes for antistatic bags - it's actually bad for an antistatic workspace to be conductive in most cases, since you don't want to be shorting out your parts at all times (like when they're powered up), but having a high resistance that's not fully insulating lets any built up charges dissipate.
 
The following users thanked this post: TomS_

Offline 1audio

  • Frequent Contributor
  • **
  • Posts: 304
  • Country: us
Re: Anti-static material - resistance
« Reply #5 on: March 06, 2019, 12:12:40 am »
I got a couple of the silicone "solder" mats from Amazon that claim antistatic properties. I have several standard antistatic mats and wanted to check these new ones against the claims. I have a 3M static control meter that reads into GOhm range and got a couple of 5 Lb weights to use as probes per the directions. On the known mats I got useful readings in the 100 meg range. Cleaning the mats made a difference. I got nothing on the silicone mats. No antistatic properties at all. If you aren't handling sensitive parts or are in an area with higher humidity its less of an issue. I would not use those silicone mats in a desert area. Otherwise they seem quite nice.  Really low resistance is not good or really high (many GOhm) resistance for static. You need enough to drain any charge slowly at low current.
 
The following users thanked this post: TomS_

Offline TomS_Topic starter

  • Frequent Contributor
  • **
  • Posts: 848
  • Country: gb
Re: Anti-static material - resistance
« Reply #6 on: March 06, 2019, 08:37:35 am »
Ok cool, so maybe not too dodgy afterall. Thanks all.  ^-^

I did the test here at the office and we only have a cheapie multimeter which evidently is probably not good enough.  :palm:  I have an 87V at home which I could try instead.
 

Offline Cnoob

  • Regular Contributor
  • *
  • Posts: 132
  • Country: gb
Re: Anti-static material - resistance
« Reply #7 on: March 06, 2019, 08:59:40 am »
https://www.ebay.co.uk/itm/IC-Integrated-Circuit-Leg-Straightener-Tool/121168020670?ssPageName=STRK%3AMEBIDX%3AIT&_trksid=p2057872.m2749.l2649

Possibly not the right page to put this on.

IC leg Straightener

If anyone needs one Ebay maybe a slightly cheaper option. It works but I've used better which a lot  more expensive
and have never attached a bonding lead to them, you just put and earth strap on yourself.



 
 


Share me

Digg  Facebook  SlashDot  Delicious  Technorati  Twitter  Google  Yahoo
Smf