A transportable, remote sensing instrument has been built that is capable of performing real-time quantitative analysis of gas and vapor contaminants of workplace air. The emphasis in this system is on simplicity and sensitivity for use over pathlengths of up to 40 m. A method was developed to overcome the effect of nonanalyte species present in the background spectrum on the quantitation of analytes in the sample spectrum. In addition, results demonstrated that instrument response was proportional to the beam pathlength under homogeneous concentration conditions. The application of software capable of qualitative analysis was also demonstrated.