What is​​​​ Tapered Element Oscillating Microbalance (TEOM)​?

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A TEOM analyser is equipment that allows the measurement of real-time (continuous) dust concentrations. A selective inlet is fitted to the TEOM to restrict the particle size being sampled to ensure that only PM10 particles are sampled for Gladstone Ports Corporation’s (GPC) compliance requirements. In conjunction with GPC's real time weather data, a TEOM can help determine the dust levels from a particular event or source and can also give an indication of the potential health effects of the dust.

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​How is it monitored?​​​

A TEOM particulate sampler operates by drawing air through a filter cartridge mounted on the tip of a hollow glass tube. The base of the tube cannot move, but the tip is free to vibrate at its natural frequency. Any additional weight from particles that collect on the filter changes the frequency at which the tube oscillates.

The electronic circuitry senses this change and calculates the particle mass rate from the magnitude of the frequency change. The instrument then returns the vibrating glass tube to its natural frequency ready for the next measurement. The instrument maintains a constant temperature and flow rate, and electronically smooths the readings to reduce noise. Dividing the mass rate by the flow rate provides a continuous output of the particle mass concentration.