| 摘要 |
PURPOSE:To measure the dynamic oscillation of the internal pressure in a bulb at the time of furnace firing by irradiating the bulb with two light waves which are mutually orthogonal linear polarized light beams and differ in frequency. CONSTITUTION:An STZL 1 generates the two light waves which are mutually orthogonal linear polarized light beams and differ in frequency. Those output beams are transmitted through the bulb 2 and a polarizer 3 and converged by a lens 4 to enter a photodetector 6 through an ND filter 5. For the purpose, a testing tube 2b is installed firstly instead of the bulb 2, gaseous nitrogen 2d is supplied, and its internal pressure is measured by a manometer 2c. Then, the STZL 1 is turned on, the phase difference between the light signal based upon the two light waves transmitted through the tube 2b and a light beat signal generated by the STZL 1 is obtained by a phase meter 7, and the pressure of the gas supplied to the tube 2b is varied to find optical retardation. The tube is then replaced with the bulb 2 and retardation is measured similarly. Thus, the retardation is monitored 7 from before the bulb 2 is turned on to the saturation of the retardation after the bulb 2 is turned on to measure the dynamic oscillation of the internal pressure in the bulb 2 in real time.
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