[volt-nuts] How to keep voltage stable in the sub-100nV range?

[David]

On Wed, 2 Nov 2016 15:11:24 +0100, you wrote:

>On Wed, 02 Nov 2016 08:44:18 -0500
>David <davidwhess at gmail.com> wrote:
>
>> Charles pretty much covered it but I am not sure that polypropylene is
>> always worse than polystyrene.  Some of the other plastic films are
>> pretty good also but polypropylene is the most common high performance
>> option.  Teflon is the best but is also expensive and has poor
>> availablity.
>
>Polyphenyle sulfide (PPS) seems to be the new kid on the block
>with quite good performance values (dielectric absorbtion, moisture
>and temperature dependence) and quite readily available.
>
>As with all film capacitors: be carefull and quick when handsoldering.
>
>			Attila Kinali

I don't know; the datasheets I checked for PPS capacitors did not list
dielectric absorption other than "low", which is always worrying, and
specified 1/2 to 1/3rd the insulation resistance of polypropylene.

In practice practically nobody is going to specify capacitors for
applications like this so the only way to really know is to test and
grade them yourself.  This is what I have always ended up doing in the
past; the datasheets were just a starting point for finding suitable
candidates.