An analyzer determining/classifying aircraft air contaminants using a contaminant collector comprises a microporous medium, a bypass; a sensor generating frequency response when contaminant mass is added to/removed from the sensor, receiving contaminants desorbed from the medium; a first sample flow path, passing through the collector; a second sample flow path, bypassing the collector; a frequency measurement device, measuring response generated by the sensor as contaminant is added to and removed; a computer readable medium bearing a contaminant recognition program and calibration data; and, a processor executing the program, the program including a module classifying the contaminant and measuring response signal magnitudes, and a module using the data for comparison with magnitude of the response generated by the sensor to calculate contaminant concentration and determine a target value for contaminant type, and using measured response magnitudes to adjust first sample flow rates and/or flow durations based upon measured response magnitudes.