DESIGNS FOR A DEPOSITION GAUGE AND A FLUX GAUGE FOR MONITORING AMBIENT DUST

The paper describes designs for a deposit gauge and for a flux gauge intended to monitor wind-borne dust. The designs are the culmination of a three-year research programme into dust and precipitation gauges. They are not yet fully characterised, but show both fundamental and practical characteristics which are considerably closer to the ideal than has been achieved hitherto. The deposition gauge resembles shallow gauges which have been described previously and are in practical use, but with the addition of a deflector ring around the gauge to improve the aerodynamic behaviour and of a foam insert to improve particle retention. The flux gauge is novel, having a through flow driven by its shape past a particle trap, the gauge shape itself also being a natural trap. The design also has directionally sensitive sampling properties, which can be usefully used for directional sampling, and is resistant to collection in reversed wind flows when used in this mode.