-----Original Message-----
From: Ian White, G3SEK <G3SEK@ifwtech.co.uk>
To: amps@contesting.com <amps@contesting.com>
To: <amps@contesting.com>
Date: 26 July 2002 20:02
Subject: Re: [Amps] Muffin Fan on Swan Mark 1
>Unfortunately IR thermometers are notoriously UNtrustworthy, unless they
>are calibrated for emissivity and - for this application - also have a
>very small spot measurement size.
>
>The temperature readings depend on the emissivity of the surface. Cheap
>IR thermometers assume a fixed emissivity of 0.95, which is a poor guess
>for bright metal and even worse for glass.
0.95 is a pretty accurate value for a dab of Tippex (don't know the US brand
of correction fluid).
Steve
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