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KF5JRV > TECH 27.08.16 13:30l 23 Lines 1215 Bytes #999 (0) @ WW
BID : 957_KF5JRV
Read: GUEST
Subj: Galileo thermometer
Path: IW8PGT<CX2SA<N0KFQ<KF5JRV
Sent: 160827/1115Z 957@KF5JRV.#NWAR.AR.USA.NA BPQ1.4.65
Galileo thermometer
Based on a thermoscope invented by Galileo Galilei in the early 1600s, the
Galileo thermometer. A simple, fairly accurate thermometer, today it is mostly
used as decoration. The Galileo thermometer consists of a sealed glass tube
that is filled with water and several floating bubbles. The bubbles are glass
spheres filled with a colored liquid mixture. This liquid mixture may contain
alcohol, or it might simply be water with food coloring.
Attached to each bubble is a little metal tag that indicates a temperature. A
number and degree symbol are engraved in the tag. These metal tags are
actually calibrated counterweights. The weight of each tag is slightly
different from the others. Since the bubbles are all hand-blown glass, they
aren't exactly the same size and shape. The bubbles are calibrated by adding a
certain amount of fluid to them so that they have the exact same density. So,
after the weighted tags are attached to the bubbles, each differs very
slightly in density (the ratio of mass to volume) from the other bubbles, and
the density of all of them is very close to the density of the surrounding
water.
73, Scott kf5jrv
KF5JRV @ KF5JRV.#NWAR.AR.USA.NA
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