QCM

QCM is an acronym that can refer to several terms depending on the field. Two widely used meanings are Quartz Crystal Microbalance and Question à Choix Multiples.

Quartz Crystal Microbalance (QCM) is a gravimetric sensing technique that uses a thin, AT-cut quartz crystal as a highly sensitive oscillator. When a mass is added to the crystal surface, its resonance frequency decreases in a way that is proportional to the mass change, allowing real-time monitoring of surface adsorption and thin-film growth. In practice, the relationship is described by the Sauerbrey equation for rigid, thin films. Modern variants such as QCM with Dissipation monitoring (QCM-D) measure energy loss to provide information about viscoelastic properties of the film and the surrounding medium. Applications include biosensing, polymer and film deposition, gas adsorption studies, and surface chemistry investigations. Advantages include label-free, real-time measurement with high sensitivity; limitations include the need for rigid films, careful temperature control, and calibration.

Question à choix multiples (QCM) is the French term for multiple-choice questions, a common assessment format in which a prompt is followed by several answer options, typically with one correct choice. Scoring is usually straightforward, but reliability depends on good item construction and avoidance of ambiguous wording. Advantages include scalability and objective scoring; limitations include the potential for guessing to affect results and the need for well-designed distractors.

Because acronyms are context-dependent, the intended meaning of QCM should be inferred from the domain, and cross-checking definitions is recommended.