PURPOSE: To perform detection of gas stably for a long period by separating and dissipating dissolved gas in liquid from said liquid by ultrasonic wave vibration, and detecting the presence of the gas and its concentration with a gas sensor.
CONSTITUTION: Water 2 to be measured is contained in a measuring container 1. A piezoelectric transducer 3 of an ultrasonic wave oscillator is inputted into the water. Dissolved gas is evaporated upward from the inside of the water. A limiting current type gas sensor 5 is arranged on the lower surface of a lid 4 at the upper part of the container 1 on the electrode side of one surface of a solid-state electrolyte which allows ions of specified gas species. A diffusion limiting body is provided in the gas sensor 5. In this constitution, the presence of even a minute amount of oxygen can be detected. In addition, the concentration of the oxygen can be measured.
YAMAMOTO HIDEO
KOMASA MINORU
OSAKI HIROZO
OKI ELECTRIC IND CO LTD
O F GIKEN KK