Abstract:

This article studies the impact of different CCD camera apertures and different powers of excitation on the calibration of a pressure-sensitive paint (PSP) by means of an optical measurement system designed and built by the researchers. Calibration experiments are performed for a PSP made in China at pressures of 27.4-147.4 kPa, apertures F between 2.8-11.0, and power of exciting light 200 W and 400 W, collecting samples 20 times at each sampling point. Calibration curves at different pressures are obtained after a series of fluorescent image processing, and analysis is made on the effect of camera aperture and excitation power on the characteristics of the PSP. The experimental results show that the influence of uneven illumination can be removed though division, and that the exciting light must be strong enough to provide the energy for the photosensitive molecules to realize energy level transition. The larger the aperture is, the greater the image signal to noise ratio is, which results in a greater slope of the calibration curve of the PSP.

Key words: pressure-sensitive paint, pressure calibration, aperture, exciting light