Active laser cavity particle counters: a fundamental problem and solution for airborne application

A previously unreported air-density-related detuning effect for active cavi ty aerosol optical particle counters is described, and a simple device for correcting the problem is presented. Airborne field tests with and without the correction device illustrate the effect and the good degree to which th e deficiency can be overcome. The effect is shown to have an important impa ct on instrument calibration. (C) 1999 Optical Society of America OCIS code s: 010.1080, 010.1100, 120.0120, 120.4820, 140.3460.