Note: A miniature oscillating microbalance for sampling ice and volcanic ash from a small airborne platform

Area of Science:

• Atmospheric science
• Instrumental science
• Geophysics

Background:

• Airborne particulate matter, such as ice and volcanic ash, poses risks to aviation and climate.
• Accurate in situ measurements of atmospheric particle mass concentration are crucial for understanding these phenomena.

Purpose of the Study:

• To describe a novel, lightweight, low-power oscillating microbalance for airborne platforms.
• To enable in situ sampling and measurement of atmospheric ice and volcanic ash.

Main Methods:

• A freely exposed collecting wire, attached to a piezo transducer, collects airborne particles.
• Mass accumulation is determined by changes in the wire's natural oscillation frequency.
• Three independent frequency measurement techniques (frequency sweep, Fourier spectral, phase-locked loop) were implemented using a microcontroller.

Main Results:

• The microbalance demonstrated agreement within ±0.3 Hz for frequency measurements.
• The instrument was successfully tested on a weather balloon up to 19 km altitude.
• High-resolution vertical profiles of mass concentration were obtained.

Conclusions:

• The oscillating microbalance is suitable for airborne platforms, including disposable use with meteorological radiosondes.
• The instrument provides a valuable tool for in situ atmospheric sampling and mass concentration profiling.
• This technology can enhance aviation safety and atmospheric research.