Patent ID: 8202478

Claim:
An observation apparatus for surveying the distribution of oxygen concentration near the bed of a body of water, comprising: a pressure-resistant container main body section that has a pressure-resistant window and is hermetically sealed by a pressure-resistant container closure section, said pressure-resistant container closure section is located at one end of the pressure-resistant container main body section of said observation apparatus; a sensor foil that contains an oxygen quenching material, said sensor foil is arranged to an outside of the pressure-resistant window located at an end opposite to said one end of the pressure-resistant container main body section of said observation apparatus, wherein said sensor is arranged only on the outside of the pressure-resistant window; an excitation light source that is arranged at the pressure-resistant container main body section to irradiate the sensor foil; an image pickup apparatus that shoots the sensor foil; and a plurality of leg sections to position the observation apparatus near the boundary of the bed of said body of water without burying the observation apparatus in the bed of said body of water so as to allow the observation apparatus to observe temporal changes in the oxygen concentration distribution at the boundary of the bed of said body of water.