Stanford Research Systems QCM200 Overview
The Stanford Research model QCM200 Quartz Crystal Microbalance measures mass and viscosity in processes occurring at or near surfaces, or within thin films. This system includes a controller, crystal oscillator electronics, crystal holder, three quartz crystals, and Windows / Mac software. The instrument reads the resonant frequency and resistance of a 5 MHz, AT-cut quartz crystal. The resonant frequency changes as a linear function of the mass of material deposited on the crystal surface. The resistance at resonance changes with the viscosity / elasticity of the material (film or liquid) in contact with the crystal surface. As a gravimetric instrument, the QCM200 can measure mass ranging from micrograms to fractions of a nanogram. Detection limits correspond to submonolayers of atoms. Observations of conformational changes, such as phase transitions, swelling, and cross-linking, can easily be made.
