Fast and accurate, the OHD FitTester 3000 provides easy-to-use quantitative fit testing utilizing the reliable principle of Controlled Negative Pressure (CNP). A fit test can be performed in as little as two to three minutes. Featuring NIST calibration, FitTester 3000 can be used as a stand-alone unit or perform fit tests through a personal computer using FitTrack software. Occupational Health Dynamics, Birmingham, AL.