| 摘要 |
PURPOSE:To attain to enhance measuring accuracy by preventing the generation of dew condensation in a detection part, by providing an air purge pipe for injecting hot air and performing the purging of air by injecting hot air to the direction of an object to be measured. CONSTITUTION:The light of a light source 2 is guided through an optical fiber 3 to be projected to an object 1 to be measured and an air purge pipe 6 having an opening 6a is provided around the outer periphery of a detection part 4 collecting reflected light from said object 1 so as to be directed to the object 1 to be measured. Hot air (warm air) A heated to a degree generating no dew condensation and cooling is injected toward the object 1 to be measured from the opening 6a to perform the purging of air. Subsequently, the detection part 4 again sends condensed reflected light to a measuring part 5 through the optical fiber 3 to measure the properties of the object 1 to be measured. Because hot air is used in the purging of air, the generation of dew condensation caused by the cooling of the optical system of the detection part 4 is prevented. By this method, highly accurate and highly reliable measurement is enabled and the damage of the object to be measured is prevented. |
