Morgan
International Hazard
Posts: 1694
Registered: 28-12-2010
Member Is Offline
Mood: No Mood
|
|
Weighing Teflon with static electricity
Kind of a fancy scale.
https://youtu.be/QafFS4izKn8
|
|
|
Sulaiman
International Hazard
Posts: 3692
Registered: 8-2-2015
Location: 3rd rock from the sun
Member Is Offline
|
|
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]
CAUTION : Hobby Chemist, not Professional or even Amateur
|
|
|
unionised
International Hazard
Posts: 5126
Registered: 1-11-2003
Location: UK
Member Is Offline
Mood: No Mood
|
|
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
International Hazard
Posts: 1694
Registered: 28-12-2010
Member Is Offline
Mood: No Mood
|
|
It might interesting to weigh electrets.
|
|
|
unionised
International Hazard
Posts: 5126
Registered: 1-11-2003
Location: UK
Member Is Offline
Mood: No Mood
|
|
|
|
|
Morgan
International Hazard
Posts: 1694
Registered: 28-12-2010
Member Is Offline
Mood: No Mood
|
|
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...
|
|
|
![[*]](images/xpblue/default_icon.gif){kind=icon}
