The XRFS runs off batteries and contains a Rh x-ray tube and an energy dispersive detector. Computer-based controllers operate the whole instrument by linking the functions of the different modules. We will have the ability, through a two-way satellite communication system, to remotely control the operating parameters of the instrument and to relay the XRFS data back to the laboratory. In practice, sample holders, containing 25 mm filters, are loaded into the carrousel. One sample holder is then moved under and pushed tightly against the air inlet by means of a motor.
Air is pulled through the filter for a set period of time.
This process can be repeated using the same filter or a new filter until the time series is completed. The ability to reuse the same filter greatly extends the time-series capabilities of this instrument. There is no point in storing a sample filter which contains no or little mass of aerosols. Consider the following scenario. If the Fe concentration is below a pre-determined level, then this filter can be returned to the inlet position for another day of collecting aerosols.