Figure 4.

Example of a three-channel image from data set surface channels displayed as an RGB image, where scalogram images of response signals from a single complete data collection step or “three-dip” test for acetonitrile are used. Each channel corresponds to the response collected from a droplet evaporation event of acetonitrile from one of the three differently treated cleaved optical fiber sensor head surfaces, namely, intrinsic (red channel), hydrophobic (green channel), and hydrophilic (blue channel).