A device to collect cohesive sediment deposits for testing in the Rotating Annular Flume is described in this blog. A photograph of the device is shown below:
The cylindrical coring device consists of two sections: The top section, which is made up of plexiglass, is 20 cm in diameter and 5 cm long. This section is for sampling the overlying water, and it connects to the bottom stainless steel section which holds the sediment core. The length of the stainless steel section is 10 cm and it has a slot for inserting a knife to cut the sediment core. The coring device has to be operated by a diver. After pressing the stainless steel chamber into the mud, the diver inserts the knife edge into the slot in the cylinder to cut the sediment deposit and to hold the deposit inside the cylinder. the sampler is then brought to the surface, when the knife is removed and plug is inserted to hold the sediment core inside the cylinder until the sample is brought to the flume for testing. The sample fits inside a sample holder in the flume. There is a provision inn the sample holder to push the sample up into the flow as the sample is eroded under the influence of the flow field in the flume. A Photograph of the sample holder underneath the flume is depicted below:
