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RE- need capacitor inform



Subject:      RE- need capacitor inform
       Date:  Wed, 28 May 1997 20:53:16 GMT
       From:  robert.michaels-at-online.sme-dot-org (Robert Michaels)
Organization: Society of Manufacturing Engineers
         To:  tesla-at-pupman-dot-com


        If you have some all-consuming need to know the dielectric
        constant of polymer films you'd best measure it yourself.
        It varies all over the south side of San Francisco, depending
        upon the polymer, its molecular weight, age, thickness,
        whether virgin or recycled, whether pure or a polymer blend,
        etc., etc., etc. (and long into the night)

        -> you are going to have to measure it anyway, in the form
           of measuring the capacitance of your finished product -
           to see what it is you have created.  You may as well
           make a preliminary measurement.

                You aren't naive enough to think that your
                finished capacitor will conform precisely
                to your calculated value of capacitance, are
                you?  (Good, I didn't think so, tho you had
                me worried for a minute, there).

        BTW - the most intelligent way to measure your dielectric
        constant (or finished capacitance for that matter) is to
        make your measurements at the voltage at which you will
        be operating the capacitor -- but you already knew that,
        right?

                                        Dielectrically constant, in --
                                        Detroit, USA

                                        Robert Michaels

        P.S.:  Same goes for volt/mil - tho it runs about 200-volts
               more or less, give or take, and depending ... for
               many polymers.



T>  From:   Mark Mackinnon <mmackinnon03-at-sprynet-dot-com>

 [ ... ]

T>I need to know the dielectric constants and voltage resistance per mil
T>of polypropelene, polyethelyne, polystyrene. etc. so I can use the
T>capacitance formula to design the cap.

T>If someone has a table with this information of can help in any other
T>way it would be much appreciated.

T>Sincerely

T>MSM