Sciencemadness Discussion Board

Weighing Teflon with static electricity

Morgan - 12-9-2021 at 16:24

Kind of a fancy scale.
https://youtu.be/QafFS4izKn8

Sulaiman - 12-9-2021 at 18:25

Just before and after I bought my analytical balance (220g x 0.1mg)
I read and watched a lot on analytical balances;
I saw that video (or similar) and others,
and found that anti-static modules are available as after market add on options.

So I tested the sensitivity of my scale to static electricity(static) ,
there can definitely be errors due to static,
even the static charge on a pair of synthetic white gloves placed on the top of the glass cover can have a significant effect,
but cotton gloves had no detectable effect.

I think that a very high voltage was applied to the ptfe in the video to get such a large display deviation.
In practice (here in Malaysia with high humidity) static has negligible effect on measured weight,
but I'd expect the effect to be worth considering in drier climates/environments.

PS static is a good reason to NOT clean the balance too often or thoroughly ;)
There are anti-static spray-on coatings available, but I've not tried any.

[Edited on 13-9-2021 by Sulaiman]

unionised - 13-9-2021 at 03:54

We just use one of these
https://www.amazon.co.uk/Milty-5036694022153-Zerostat-Anti-S...

though the microbalances have small radioactive sources in them to limit the problem.

You can fix the problem completely by weighing things in a conductive container.

Morgan - 13-9-2021 at 18:50

It might interesting to weigh electrets.

unionised - 14-9-2021 at 04:04

Quote: Originally posted by Morgan  
It might interesting to weigh electrets.


Quote: Originally posted by unionised  


You can fix the problem completely by weighing things in a conductive container.

Morgan - 14-9-2021 at 06:53

Quote: Originally posted by unionised  
Quote: Originally posted by Morgan  
It might interesting to weigh electrets.


Quote: Originally posted by unionised  


You can fix the problem completely by weighing things in a conductive container.


I wonder what kind of a scale they were using here?
"The mixture was 45% carnauba wax, 45% resin, and 10% beeswax. In 21 hours the weight increased over 30mg. A particular point is the sudden weight increase of around 4 mg after 5.5 hours. b shows a diagram of the electrostatic field of another similar electret."
https://www.researchgate.net/figure/a-shows-the-weight-measu...