A method and system for detecting and classifying sensor data, includes obtaining at least one feature vector from a sample to be analyzed, the sample to be analyzed being applied to an array of sensors that includes at least two differential sensors. The method and system also includes converting the at least one feature vector to at least one ratio -metric feature vector. The method and system further includes comparing the at least one ratio-metric feature vector to a detection threshold, and outputting an alarm to denote that the sample is abnormal when the detection threshold is exceeded. When the at least one ratio-metric feature vector does not exceed the detection threshold, the method and system includes classifying the sample as normal and feeding back the at least one ratio-metric feature vector to recompute the detection threshold for future samples to be detected and classified.
ADAPTIVE DIFFERENTIAL RATIO-METRIC DETECTOR