Temperature measurements using pulsed photothermal radiometry and silver halide infrared optical fibers

Abstract

A novel technique for measuring temperature, based on pulsed photothermal radiometry and analysis of the spectral and temperature dependence of Planck’s blackbody equation, is described. In this technique a body is irradiated by a laser pulse and its temperature inferred from the time dependence of the emitted infrared signal curve. This technique was used for near ambient temperature measurements using a CO2 laser, an infrared detector, and infrared transmitting silver halide optical fibers. The experimental results are consistent with theory. This technique is independent of changes in emissivity or geometric factors and it will be useful for accurate and fast noncontact temperature measurements.

Effects of Temperature and X-rays on Plastic Scintillating Fiber and Infrared Optical Fiber

“…Next, in the cases of FOTs, they normally use a silver halide optical fiber as an infrared optical fiber (IR fiber) to measure temperature by transmitting IR signals emitted from a heat source [ 17 , 18 , 19 , 20 , 21 , 22 ]. As a non-contact temperature sensor, those based on IR fibers have been fabricated to use in examination or treatment rooms where magnetic resonance imaging (MRI) or radiofrequency ablation (RFA) devices are installed [ 20 , 21 ].…”

Applications of fiber optic pulsed photothermal radiometry

“…We constructed and tested a fiber optic PPTR setup based on silver halide optical fibers, which have good transmittance in the mid IR. In a previous work, 8 we discussed the fiber optic PPTR experimental setup for temperature measurements, where the temperature was inferred from the decay time of the pulsed photothermal signal. In this paper we show the feasibility of fiber optic PPTR for measurements of thermal properties that relate to industrial and medical applications.…”

“…It is a noncontact method enabling a convenient, nondestructive, and ''remote'' measurement of a sample's thermal and physical properties, 1,2 such as thermal diffusivity, heat capacity, thermal conductivity, absorption coefficient, thicknesses of coating and thin films, [3][4][5] and the temperature of a sample. [6][7][8] Quantitative values can be obtained by analyzing the shape of the time dependence of the emitted signal. The PPTR method was used in medical applications to distinguish between normal and diseased biological tissues [9][10][11][12] and to assist in laser surgery.…”

Semi-empirical approach for the analysis of infrared photothermal microscopy

“…In principle, there are no difficulties in doing the experiments with such a laser, except for the necessity to insert a filter in front of the IR detector to prevent it from being directly irradiated by the pump beam. 3 Alternatively, an InSb detector insensitive to the 10.6 m pump wavelength can be used.…”