Photoacoustic spectrometer

摘要

By the use of one or more beams of chopped, variable-frequency, monochromatic light to illuminate the sample chamber of at least one gas-filled cell including such sample chamber and a reference chamber joined to the sample chamber by a tunnel-like opening or orifice which permits fluid communication between the chambers and incorporating a thermal-flowmeter-type sensor element in the path of flow of the fluid between the chambers of each such cell, the compositional characteristics of one or more samples in each sample chamber can be determined accurately.