THE DESIGN OF A SENSITIVE LOW FREQUENCY COUPLED RESONANT PHOTOACOUSTIC CELL

This paper describes the structure and characters of a coupled resonant photoacoustic cell whichhas a smaller volume and operates at the modulation frequency of several hundred Hz.By the adop-tion of transverse exciting light and differential receiving the detection SNR is increased.Its detec-tion sensitivities for concentration of CH_3OH and C_2H_4 have reached 1.2×10~(-9)/W Hz~(1/2) and4.2×10~(-9)/W Hz~(1/2) respectively.