Figure 6
Multimode sensing and detection limits. (a) Estimated RH sensitivity achieved by measuring capacitance (C1), DC resistivity (R/R0), QCM frequency shift (ΔM), and optical constants (n) for RH sensing. Shaded regions represent uncertainty range. Right axes show estimated measurement sensitivity of each technique. Axes units are shown in plot legend. (b) Top panel: display of RH sensing limit of mass-based measurements showing ΔM as calculated from frequency shift of CuPcTs-coated QCM crystal (black) and bare gold-coated crystal (red). Bottom panel: Two pulses of H2O vapor corresponding to ~0.15% RH which is detected using CuPcTs-coated QCM.
