Bryan,
A few questions:
1) Are you sure all lab sites are doing this by wet chemistry?
2) Are they all using the same method (ie all the same possible
interferences)?
3) Does anyone know the natural variation in tin concentration in a
supposedly homogeneous molten bath?

regards,
Bev Christian
Nortel Networks

> -----Original Message-----
> From: Bryan Kerr +44 1383 822131 ext 4409 [SMTP:[log in to unmask]]
> Sent: Monday, February 15, 1999 8:57 AM
> To:   [log in to unmask]
> Subject:      Re: [TN] solder composition
> Sensitivity:  Confidential
>
> It is my experience that the analysis of Tin in solders is not the most
> accurate and reliable test, normally done by wet chemistry. OK the test
> house
> may claim + or - 0.01% however I have had samples re-tested before and had
> differing results obtained. I would advise having samples re-tested and be
> absolutely sure of your tin level before considering messing around with
> the
> tin content by adding more tin. A good guideline is to calculate the
> theoretical weight of tin lost since the last analysis. If it's several
> kilo's,
> you'll know that there's something amiss with the test result !
>
> Bryan Kerr
> Alenia Marconi
>
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