Direct Gravimetric Calibration of a Quartz Crystal Microbalance

Abstract

A commercial quartz crystal microbalance has been calibrated via simultaneous comparison with a reference vacuum electrobalance. Aluminum, copper, and gold thermally deposited on 10 MHz AT‐cut oscillators gave a composite linear calibration to a precision of ±0.2%. For a uniformly distributed deposition, the ratio K of the fractional change of mass Δm/m to the fractional change of frequency Δf/f is shown to be 0.991 with a probable error of 0.6% for a configuration having peripheral contact restraints of the oscillators. The response function δf/δm (sensitivity variation over the face of the crystal) was determined to exhibit asymmetries about the central axes.