| 摘要 |
ABSTRACT The device (105) for sampling air with a view to analysing and measuring the quantity of particles, in particular asbestos, fibres and/or metals, in atmospheric suspension, is characterised in that it comprises: - an air sampling inlet (110), - a pump (125) linked to said air sampling inlet, - a filter (135) designed to retain particles in suspension in the pumped air, - a mass flow meter (140) designed to measure the mass flow rate of air traversing the filter, - a pressure sensor, - a temperature sensor, - a sensor of the level of moisture in the air, - a modulation means (145, 160, 165) for modulating the flow rate of air traversing the filter and - a means (150) for the servo control of the modulation means on the basis of the mass flow rate, the temperature, the level of moisture and the atmospheric pressure designed such that the measured flow rate, expressed as moles of dry air per unit of time, is substantially constant. In certain embodiments, the modulation means comprises a proportional valve (160). (Figure 1) |
