Poh, Lei,
I have always treated SG measurements as suspect.  Not because the
hydrometers don't work, but do you know what you are measuring?  How do you
know whether the density change is due to concentration of the flux because
of alcohol evaporation or due to water absorption from the atmossphere?
I'll take an acid/base titration any day, thank you.

regards,
Bev Christian
Nortel

> -----Original Message-----
> From: Tumibay, Aleli [SMTP:[log in to unmask]]
> Sent: Tuesday, December 01, 1998 8:48 PM
> To:   [log in to unmask]
> Subject:      Re: [TN] : Flux activity monitoring system
>
> Hello Poh:
>
> > Is there any way to monitor the flux activity level, as to check whether
> > the flux has been degraded over time, using the foam fluxer ?
> >
>         There is a formula I copied from a book once that determines the
> fluxing
> power of the rosin a.k.a. its "acid value" through
> neutralization/titration
> techniques.  I did not get to use it though because *simple monitoring of
> flux
> specific gravity* works good enough for us.
>                           mg of KOH to neutralize a rosin sol'n in alcohol
>  ACID VALUE  =
> -------------------------------------------------------------------------
>                          gram of dissolved rosin
>         An acid value of 160-180 is considered adequate for a good rosin.
>
> Lei Tumibay
> Lead Finish Group - Assembly Engineering
> Analog Devices - General Trias
> Cavite, Philippines
> E-mail: [log in to unmask]
> http://www.analog.com
>
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