GB1360346A - Sampling device - Google Patents

Abstract

1360346 Sampling liquids A Q KHAN 26 March 1973 [12 April 1972] 16821/72 Heading B8N A device for continuously sampling rivers, sewage effluent or liquid passing along a channel 10 comprises extraction means such as a submersible pump 11 and cylinder 13 for continuously extracting liquid and providing a head of liquid, and sample collecting means 20, 22 and 28 having an overflow 24 at a predetermined level relative to the level of the head of liquid according to the desired sampling rate. As shown, liquid with suspended particles is continuously circulated up through the cylinder 13 and back to the channel 10 through a down-pipe 15 by the pump 11. A sample take-off pipe 17 is connected to the overflow 24 via a settling chamber 20 and the height of the overflow is adjustable to obtain the desired rate at which the liquid and suspended particles can be collected in a vessel 28. The height of the overflow 24 may be fixed or automatically adjusted in accordance with the rate of flow along the channel 10 by means of a float 30 and a band 31 which passes over a rotatable cam 32; alternatively, the height may be adjusted by use of a servo system operating according to a signal from a flow integrator. At the end of a sampling period, a valve 19 is closed and a valve 29 opened to release the particles accumulated in the settling chamber 20 and the liquid remaining in the collecting means into the vessel 28. A weir may be provided in the channel 10. When oil free from suspended particles is being continuously sampled, the settling chamber 20 can be omitted. Samples could be passed to individual containers on a time basis.