The radial sensitivity function of a quartz crystal microbalance (QCM) Is found to be altered by the presence of a heavily stressed film on one face of the crystal. The sensitivity of the center of the crystal Is found to Increase drastically while the peripheral area Is found to become very insensitive to mass changes. The overall (Integral) sensitivity of the crystals to a mass change is shown to be unchanged. The need for a uniform dose over the entire active area of the crystal In order to obtain meaningful data is emphasized.

No abstract