Abstract: By the sampling requirement of sodium fluorescein method, a sampling filter performance-testing device was established using sodium fluorescein as aerosol agent. Seven glass fiber filter's resistance, background fluorescence and filtration efficiency of sampling flow rates from 0.92 to 2.75 m/s were measured, and then filter performance's influence on the purification factor was analyzed. Results show that the filtration efficiency of filter membrane has little effects on the purification factor of HEPA filter for the tested relative error of CF-A, FP5211 and GC90 are as low as 0.014%, 0.063% and 0.082% respectively. Mean while, effects of background fluorescence on system purification factor is obvious when the concentration of soaking solution is low; if the resistance were too large to limit collection of sodium fluorescein, it could increase interference of background fluorescence values. This study can provide guidance for evaluation, selection and usage of sampling filter.

Key words: sodium fluorescein, HEPA filter, sampling filter, fieldtest, purification factor