ISSN:
1432-1114
Source:
Springer Online Journal Archives 1860-2000
Topics:
Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
Notes:
Abstract The characteristics of an optical fiber thermometer (OFT) having a black body cavity sensor, constructed with a thin platinum film sputtered on a sapphire rod tip, were examined and compared with those of bare or sheathed thermocouples. For time averaged temperature measurements by the OFT, the radiative heat loss is significant in the temperature range of flames. For fluctuating temperatures the OFT output has a slow response, due to its thermal inertia, which depends on the diameter of the sensor and flow conditions; in spite this the rapid response of the OFT is emphasized in the literature with the assumption of the ideal thermal behavior of the thin sputtered film ( ⩰ 4 μm) on a sapphire rod of 0.25 mm diameter. The fluctuation waveform predicted by the present numerical simulation agrees satisfactorily with the measured one, which proves that the major factor affecting the thermal inertia of an OFT sensor is the heat capacity of sapphire. A special compensation technique is needed to improve the response of the OFT.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF00196597
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