NTC - Yep, you EEs keep on thinking you are in charge.   Meanwhile, my
minions and I will keep on sneaking up on you - "The future of electronics
is chemical"
https://phys.org/news/2018-07-future-electronics-chemical.html

On Wed, Jul 18, 2018 at 7:22 PM Yuan-chia Joyce Koo <[log in to unmask]>
wrote:

> that's scary.
> On Jul 18, 2018, at 11:48 AM, John Maxwell wrote:
>
> > High dielectric constant ceramic capacitors all exhibit aging due
> > to the crystal structure changing from ferroelectric (tetragonal or
> > diamond) to paraelectric (cubic) structures. Higher the dielectric
> > constant (k) and the thinner the dielectric the more rapidly the
> > parts age or lose capacitance.
> >
> > John
> >
> >
> > Sent from my iPhone
> >
> >> On Jul 18, 2018, at 11:10 AM, Guy Ramsey <[log in to unmask]>
> >> wrote:
> >>
> >> Well, I'll Be.  I cooked them at 150C for an hour and they measure
> >> 100uF
> >> I learned something today.
> >>
> >>> On Wed, Jul 18, 2018 at 8:08 AM <[log in to unmask]> wrote:
> >>>
> >>> Guy,
> >>>
> >>> Read this and try putting the parts through their Curie point and
> >>> test
> >>> them again.  We have seen this on some parts here.
> >>>
> >>> https://www.johansondielectrics.com/ceramic-capacitor-aging-made-
> >>> simple
> >>>
> >>> Drew
> >>>
> >>> -----Original Message-----
> >>> From: TechNet [mailto:[log in to unmask]] On Behalf Of Guy Ramsey
> >>> Sent: Wednesday, July 18, 2018 7:00 AM
> >>> To: [log in to unmask]
> >>> Subject: [TN] capacitor measurement
> >>>
> >>> I got pulled into a Receiving Inspection problem. Our test
> >>> instrument, an
> >>> old HP 4192A impedance meter, and a newer Instek 6020 tell us
> >>> that our X5R
> >>> capacitors are out of spec.
> >>> A 100uF, 10%, 6.3V capacitor measures between 25% and 30% below the
> >>> nominal value.  The instruments have Kelvin probes and are zero
> >>> calibrated
> >>> at frequrency, 120Hz the test waveform is 500mV rms.
> >>> Does anyone have any advise?
> >>>
>