Indexes for evaluation of dynamic characteristics of pressure-sensitive paint based on pressure sensitivity and frequency response

Abstract

Two evaluation indexes were proposed to select the optimal PSP for unsteady pressure measurement from various PSPs with different pressure sensitivity and frequency response. An effective sensitivity coefficient calculated by pressure sensitivity and gain attenuation due to the response delay was proposed. Furthermore, an effective amount of intensity change was recommended, which takes into account the emission intensity and the effective sensitivity coefficient, because the magnitude of the intensity of a PSP is also important for unsteady-pressure measurement with high-speed sampling. 
A total of five types of PC-PSPs developed in previous studies were compared: two types of fast-response PC-PSPs using Pt(II) meso-tetra (pentafluorophenyl) porphine (PtTFPP) with poly(isobutyl methacrylate) (poly(IBM)) and ruthenium complex with RTV silicone, respectively, and three types of PC-PSPs using PtTFPP with poly[1-trimethylsilyl)-1-propyne] (poly(TMSP)). A comparison was made using the proposed evaluation indexes under various pressure ranges. The results showed that poly(TMSP)-based PC-PSP has a high effective sensitivity coefficient at pressures less than 20 kPa. On the other hand, poly(IBM)-based PC-PSP has the highest effective sensitivity coefficient at a pressure of 100 kPa. 
The effective amount of intensity change of poly(TMSP)-based PC-PSP is the highest at 2 kPa, but that of poly(IBM)-based PC-PSP is the highest at a pressure higher than 5 kPa among the evaluated PC-PSPs due to its high luminescence intensity.
A PSP with high emission intensity will provide high performance in terms of fluctuation of emission intensity detected by the photodetector when the excitation intensity and the exposure time are limited due to limitations of optical equipment or high-speed sampling.

A wide range oxygen sensing strategy with the collaboration of multiple phosphorescence probes

“…Conversely, oxygen probes with low sensitivity are often neglected in development and application. It is obvious that high accuracy measurement of wide range oxygen requires the collaboration of several oxygen probes with different sensitivities, and the oxygen measurement capability is the main basis for selecting the optimal oxygen probe [27,28]. Currently, the results of such a presentation of the oxygen probe's measurement capability are incomplete, limited accuracy data mainly comes from experimental measurements at discrete concentrations, which is due to the lack of a well-developed theoretical evaluation method of the measurement capability [29].…”