Differential spectrophone measurements of the absorption of laser energy by atmospheric dust

The use of the differential spectrophone to measure atmospheric particulate absorption is described. This device reduces window signals and is used to obtain increased sensitivity. A block diagram of the differential spectrophone system using a tunable CO sub(2) laser source is presented, and its operation and calibration are described. Spectrophone experimental results are presented, and the advantages and disadvantages of the device are considered.