Lamps, dust observation

Qualitative monitoring techniques include smoke tubes and the dust observation lamp. Smoke tubes generate a white smoke which may be used to indicate the direction of flow of air - this is particularly useful when the air speed is very low or when testing the effectiveness of ventilation ducting. A dust observation lamp enables dust particles which are normally invisible to the human eye to be observed in the light beam. This dust is usually in the respirable range and, although the lamp does not enable any measurements of the dust to be made, it will illustrate the operation of a ventilation system and the presence of such dust. 

MDHS 82 The dust lamp - A simple tool for observing the presence of airborne particles... 

HSE. The Dust Lamp—A Simple Tool for Observing the Presence of Airborne Particles. MDHS 82. London HMSO, 1997. 

Thus, if a portable lamp having a strong parallel beam is set up to shine through a dusty environment, the movement of the particles can be observed. Although this is not a quantitative method, the behaviour of the dust emitted by the work processes can be observed and corrective measures taken. It may be useful to photograph or make a video record of the observation. 

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