Abstract
We improve a spatial resolution of concentration measurement system based on the light absorption spectrometric method. The light source of the system is upgraded from a halogen lump to light-emitting diodes (LEDs). We also develop an optical fiber probe with a smaller sampling volume than that of the former system. The performance of the concentration measurement system is tested in a turbulent planar liquid jet with a second-order chemical reaction. The concentrations of chemical product and non-reactive species are measured. The results show that the mean concentrations measured by the new system are consistent with those measured by the former system. However, the new system enables to measure the concentration fluctuations at higher frequencies than the former system.
