An intensity-based and a lifetime-based PSP imaging method with enhanced sensitivity   

 

S.Someya1, S.Yamashita1,2, T.Munakata1, H.Ito1,  
1 National Institute of Advanced Industrial Science and Technology, 1-2-1 Namiki, Tsukuba, 

Ibaraki 305-8564, Japan 
2 The University of Tokyo, 5-1-5 Kashiwanoha, Kashiwa, Chiba 277-8563, Japan 

 

A pressure-/temperature-sensitive paint (PSP/TSP) has been developed and used as a 

measurement tool for the two-dimensional distribution of pressure and temperature on 

aerodynamic surfaces. In recent years, although the concern with measuring a pressure 

difference of several Pa, such as countermeasures against the noise of small fans, has been 

growing, the resolution of current PSP measurements is limited to several 10 Pa, even with 

carefully conducted measurements. For highly accurate measurements, researches on the 

advanced coating films in PSP/TSP have eagerly been conducted to date. However, 

measurement resolution and accuracy deteriorate when quantum efficiency or lifetime 

decrease under high pressure or high temperature conditions.  

In this study, we propose an advanced evaluation method by improving an imaging procedure, 

by combining intensity-based and lifetime-based methods. It is expected to improve accuracy 

as compared to the case where a single method is used. We evaluated the pressure 

sensitivity and temporal fluctuation of measured values, with comparing to a standard 

intensity-based method and a standard lifetime-based method under steady and unsteady 

pressure conditions.  

Due to the limitation of the length of extended abstract, two standard and two proposed 

concepts of imaging procedure were illustrated in figure 1 and 2. Here, we defined the method 

which required a reference image as the intensity-based method, and the method without 

any reference image as the lifetime-based method.  

 

Fig.1 A concept of revised intensity-based method with a reference image. 



 
Fig.2 A concept of revised lifetime-based method without a reference image. 

 

Fig.3 Pressure sensitivities of standard and proposed imaging methods near the 

atmospheric pressure condition. 

 

Figures 3 show pressure sensitivity of each method near the atmospheric pressure. As 

shown in figs.3, proposed methods had higher pressure sensitivity than those of standard 

methods. The high sensitivity leads to a large value of the signal-to-noise-ratio and clear 

visualization of pressure distribution.  

In the full length paper and the presentation, detail of these methods and results are 

shown.