P-72 Sampler

HIF/FISP Part # 4102006

The US P-72 is a point-integrating suspended-sediment sampler that has an electrically operated valve for starting and stopping the collection of a sample. The sampler is lowered to the desired depth in the water column, the sample collected by remotely opening and closing the valve, and then the sampler raised is to the surface for removal of the sample container.

The sampler has a streamlined cast aluminum body 28 in long that weighs 41 lbs. It has tail fins to orient the sampler so that the intake nozzle in the head points directly into the approaching flow. The sampler head is hinged to provide access to the pint or quart bottle sample container located in a cavity in the sampler body. An exhaust port pointing downstream on the side of the sampler head permits escape of air from the sampler container as it is displaced by the sample being collected. The sampler uses a 3/16-in internal diameter nozzle and can be used in stream velocities ranging from 1.5 to 5.3 ft/sec. It can be used to a depth of 72 ft with a pint container and 51 ft with a quart container.

To eliminate sudden inrush at a selected sampling point below the water surface, the diving bell principle is used to balance the air pressure in the bottle with the hydrostatic pressure at the nozzle prior to opening the valve at the start of sampling. The “diving bell” in the sampler is the body cavity behind and surrounding the sample container. It is connected by ports through the valve system to the surrounding stream and to the sample bottle.

The operating current may be supplied by the US RBP-06 rechargeable battery pack, which is sold separately. HIF Repairable.

Where and how the sampler is deployed in the field is as important as the fundamental design of the sampler. Additional information about how to properly use this sampler can be found in the following references:

Edwards, T.K., and Glysson, G.D., 1999, Field Methods for Measurement of Fluvial Sediment: U.S. Geological Survey Techniques of Water Resources Investigations, book 3 chapter C2, 89 p.

Associated Components

4108003 ADAPTER SLEEVE, PINT FOR P-61 AND P-72
4108006 BOTTLES, QT, GLASS
4108015 GASKET, HEAD
4108019 HANGER BAR AND PIN FOR P-61-A1 & P-72
4108031 LIDS, 70 MM (004080) FOR QT BOTTLE
4108035 NOZZLE, BRASS, 3/16 IN.
4108040 US RBP-06
4108045 SOLENOID