Piezoelectric contamination detector

US4561286A · kind A · utility

Assignee

• Laboratoire Suisse de Recherches Horlogeres · CH

Inventors

• Jorg Sekler · Neuchâtel, CH
• Alphonse E. Zumsteg · Solothurn, CH
• Hans E. Hintermann · Riedlingen, DE

Key dates

• Filing date: Jun 28, 1984
• Grant date: Dec 31, 1985
• Expiry date: Jun 28, 2004

Classification

• Technology area (CPC G): Physics
• CPC primary: G01N2291/02881
• WIPO field: Measurement
• WIPO sector: Instruments

Abstract

A piezoelectric detector for determination of the mass or film thickness of gaseous, liquid or solid substances being adsorbed or condensed on the surface of a piezoelectric resonator, having at least one measuring resonator with at least one integrated thin-film sensor, one discrete or integrated on the resonator re-evaporation heating element, and a reference resonator separated from the measuring resonator with a contamination shield, and protected from contamination, but not from heat radiation, with an optical window, which all allow correction by electronic or numerical means of influences of temperature changes on the resonant frequency and of cut-angle deviations and the temperature differences between the resonators.