| 摘要 |
PURPOSE: To measure the thermal conductivity of a medium to be measured and to measure the mixture ratio and flow velocity of the medium on the basis of the thermal conductivity by preparing a temperature gradient positively by heating an optical resonator. CONSTITUTION: An optical resonator 1 is immersed in a medium 7 to be measured. When both of them come to steady states of the same temperature, a laser light of a 1.55μm band is made to enter the resonator 1 from a light source 2 for monitoring through an optical waveguide 3 and a resonant wavelength is monitored. The temperature T1 of the resonator 1, i.e., of the medium 7, is determined on the basis of this resonant wavelength. Next, a light of wavelength 0.80μm is emitted from a light source 4 for heating light through an optical waveguide 5 so as to heat the resonator 1. At the time when the quantity of the irradiation heat balances with the total quantity of radiation and a steady-state temperature distribution is brought about, the laser light of the 1.55μm band is cast from the light source 2 and a reflected light is monitored. The temperature T2 of the resonator 1, i.e., of the medium 7, is determined on the basis of the wavelength of this reflection and the effective thermal conductivity of the medium 7 is calculated from a temperature gradient of the temperatures T1 and T2 . The mixture ratio and flow velocity of the medium 7 can be measured on the basis of this thermal conductivity.
|
