|BIOMEDICAL FIBEROPTIC THERMOMETER: Principle of Operation|
IRE MT-04 principle of Operation
The IRE MT-04 utilize a new temperature sensor technology based on the temperature dependence (Fig. 1) of a luminescence decay time of the special patented glass material excited by short pulses of light emitting diode (LED). The small piece of such glass is located on the tip of a multimode optical fiber which is used for delivery of the LED excitation pulses, also as to return a glass luminescence response into a photodetector.
Fig. 2 shows scheme of the signal processing unit. A LED (2) produces an exiting pulse (wavelength 800 nm) which is transmitted down the fiber (4) to the sensor (5) causing it to fluoresce (Fig. 1). The fluorescent signal is transmitted back to the instrument by the same fiber , rejected by a spectrum splitter (3) and focused onto a photodetector (6). The fluorescent decay time is measured by microprocessor (8) which also is controlled a modulator (1), keypanel (9) and display (10) and converted the measured decay time to temperature