Page 111 - My FlipBook

The "thermo-couple system" is the one generally used by the manu-
facturers of dental pyrometers. The pyrometer may be divided into two
parts, the first being the "thermo-couple," or portion that is introduced
into the niutfle of the furnace, and second, the milli-ammeter or milli-
voltametcr that registers the tem]X'rature of the mutfle. The "thermo-
couple" is usually composed of a small spherical shaped mass of rhodium.

Fig. 121.

to which is attached two heavy platinum lead wires. In some instances
two of these elements are used or connected in series in order to secure
a greater volume of current for the purpose of actuating the recording
instrument. This element is a miniature heat battery, that is, when it
is exposed to heat it will generate a feeble current which increases or
decreases according to the variations of temperature that takes place
within the muffle. This feeble current so generated is in turn measured

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