The Watertrap water sampler has been designed to take representative samples from running water up to a depth of approximately 25 metres. Samples are taken with the stainless-steel device by catching part of a horizontal moving column at a certain moment at a certain depth. The sampler is also suitable for high current waters.
Method
The water sampler is lowered by the included hand winch fitted with a steel cable. The winch is attached to a telescopic arm; an attachment clip allows the unit to be fixed to the railing of a bridge or boat. The depth at which the sampler is located can be read from a depth counter. The spring-loaded valves are set open before the sampler is lowered and keep te valves in an open position.
As soon as the sampler is positioned at the right depth, the falling weight is released and slides down along the cable; at the end the weight is hitting the arms of the clamps, resulting in the closing of the downstream valve first, followed only a moment later by the upstream valve.
The valves have rubber seals to ensure a watertight enclosure of the sample during retrieval. By opening the valves, the sample can be discharged. By relocating the weights and adjusting the fins, it is possible to hang the sampler in any required position. For correct sampling it is important that the water sampler is suspended in balance in the water. Bringing the sampler in balance can be achieved by:
- Adjusting the horizontal tail fin
- Sliding the tail fin rods through the guiding tubes
- Altering the weight under the front of the stainless-steel cylinder
SCOPE OF DELIVERY
- The stainless-steel water sampler
- Falling weight
- Hand winch unit with 25 metres steel cable
- Telescopic arm with fastening clip and depth counter
- Transport case
- Cleaning and maintenance accessories
