For the testing phase, we generate a synthetic data set of sensor response vectors under both normal and anomalous conditions. The test data set constitutes 120 (m i , i ) pairs (100 normal, 5× each anomalous condition), where m i is the response vector of the sensor array to a gas composition under a condition i ∈ {normal, CO 2 ↑, C 2 H 4 ↑, C 2 H 4 off, CO 2 &C 2 H 4 ↑} in the fruit ripening room. Each data point represents a snapshot of the equilibrium response of the sensor array inside the room at one point in time. Again, we sample a gas composition from the probability distribution in Fig. according to the label, then invoke the adsorption model in eqn. 1 to sample the associated response vector of the sensor array (σ m = 10 -5 g gas/g ZIF, σ H 2 O = 0.01 [RH]).