A temperature insensitive quartz microbalance

Dual mode excitation of the fundamental mode and third overtone c-modes of an resonator allows highly accurate temperature sensing over wide temperature ranges. SC-cut resonators are also thermal transient compensated. These unique properties allowed the development of a temperature compensated microbalance which is highly sensitive to mass changes, which can be used in rapidly changing thermal environments, over wide temperature ranges, and which requires no temperature control. To demonstrate the performance of this microbalance, SC-cut resonators were coated with thin polymethylmethacrylate (PMMA) photoresist films and then placed into a UV-ozone cleaning chamber which was initially at about 20°C. When the UV lamp was turned on, the UV-ozone removed PMMA from the surfaces while the chamber temperature rose to about 60°C. The frequency changes due to mass changes could be accurately determined, independently of the frequency changes due to temperature changes