It is important to understand the behavior of oxygen concentration distribution inside micro-channels for the improvement of micro devices or fuel cells. Most of oxygen sensors such as galvanic or polaro-graphic type cannot be used for unsteady measurements in a small system because of their long response time and large probe heads. We focused on pressure sensitive paint (PSP) for the measurement of the oxygen concentration dissolved in the water in a small system. Up to the present, the PSP techniques have been mainly applied to gas-flows. However, the PSP technique is based on the oxygen quenching of luminescent molecules and would be used in both gas and liquid-flows. In this paper, we investigated the oxygen sensitivity of three types of PSP in the water, and selected a suitable polymer for a binder of PSP.
