| + Met Index | AUTOMATIC FOG SAMPLERA fog water collector based on the impactor principle. |
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Tel UK: 01275 847787 Fax UK: 01275 847303 ______________________ |
Automatic
Fog Sampler Model ANES The model ANES Fog Sampler is designed to accurately measure the amount of moisture in fog. The sampler monitors the weather conditions and automatically switches on during periods of fog to collect the water. With a controlled heating and cooling system for the samples the ANES can be used for all year operation.
How the fog is collected The air is sucked in at a rate of rd. 120 m³/h through a twin nozzle behind a specially designed deposition body onto which the fog droplets are impacted. The deposition body has a vertically oriented hole in its centre which is connected to the impaction surface by numerous small bored holes. The centre hole and the instruments exits are connected by tubes so that a slight under pressure is applied sustaining a slight air flow through the capillary holes. The deposition body has a small rim at each side preventing the deposited water from being ripped off and carried away with the fast air stream. The fog droplets which are deposited coagulate and this water is sucked into the small holes due to capillary forces and under pressure and drains into the centre from where it flows into the collection device. By this way a rapid separation of the collected water from the strong air stream behind the nozzle is reached and problems as evaporation or continuing reactions are minimised. Behind the nozzle the air is guided by semicircular surfaces to the exit in order to avoid turbulences.
A laser based visibility sensor (ONED 250) detects the visibility of the fog. When the visibility is below a set point for a certain time the control electronics start the vacuum pump which sucks fog through the fog sampling device. When the visibility is above the set point for a certain time the pump is stopped. The sampling process is also stopped whenever the ambient temperature is below 2°C in order to prevent the twin nozzles being blocked by ice.
Optional Items Data logging The basic information as switching on/off the pump; ambient temperature and humidity can be logged by an (optional) data logger, which is built into the main housing. Stand The ANES fog sampler can be mounted onto an optional steel and zinc plated stand.
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Links to previous pages Tel UK: 01275 847787 Fax UK: 01275 847303
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Manual Fog Sampler This sampler operates in the same way as the ANES model above but without the automatic controls. The air is sucked in at a slightly higher rate of 125 m³/h and the samples are collected into two collection bottles. As it is not automatic the sampler has to be manually switched on during fog events.
Specifications are subject to change without prior notice. E&OE. If you are interested in either of these fog samplers please do not hesitate to contact us by email at wwwmet@biral.com Thank you for visiting www.biral.com/met/precipitation/samplers.htm |
