ISSN:
1089-7623
Source:
AIP Digital Archive
Topics:
Physics
,
Electrical Engineering, Measurement and Control Technology
Notes:
A fast broadband pyrometer with a spatial resolution of 2 μm and an accuracy of 10% in temperature is described plus a calibration method suitable for liquid metals. The time resolution of temperature measurements is limited by the electronics rise time (3.5 ns) to 14 ns (10%–90% rise time) of a temperature change because of the nonlinear relation between electronic signal and temperature. The pyrometer was applied to determine the temperature of melts produced by focused nanosecond laser pulses in gold and iron films. Measured heating rates (1010–1011 K/s) and peak temperatures (3000 K) are correctly reproduced by numerical simulations for gold, but theoretical peak temperatures in iron were 1000 K in excess. The low actual temperature in iron can be explained by native oxides, decomposing during the laser pulse and thus dissipating energy. This effect may cause considerable differences between computed and actual temperatures during laser processing of thin metal films with unstable impurities. © 1997 American Institute of Physics.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1063/1.1148155
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