|Article number:||185681 + 185683 + 185687|
|Availability:||Out of stock|
|Delivery time:||1-4 Weeks|
The Hess sampler is used in similar circumstances to a Surber Sampler but is even more accurate. The base of the Hess sampler is pushed into the substrate to make a seal. Two strong handles allow for forcibly pushing and rotating the cylinder into the stream bed. For use on harder substrates, the Hess Sampler is also available with teeth for cutting into the substrate, effectively converting the sampler into a cylindrical corer or stovepipe sampler.
The upstream side is sealed with a large upstream filter of preferred size to prevent any invertebrates entering the sampler through drift or when the external substrate is disturbed. The downstream side has a net bag fitted with a closed, screw on filter. Similar to a plankton net in shape, this bag will collect any invertebrates within the sample area. An expression of the number of invertebrates in relation to surface area sampled can then be calculated.
The sampler is robust enough to use in a tidal estuary where the upstream filter is severely tested. The upstream filter is affixed with velcro so it's easily removable and washed for reuse.
The Hess Sampler is fully customisable so it will always fit your needs. By specifying both the upstream and downstream filters it is also possible to selectively sample the water column.
The Hess Sampler includes everything you need: the metal pipe, nylon collar and jubilee clip for affixing the downstream filter and net. You will also need to choose:
Downstream Net and Filter: