Performing unfiltered sampling into your Silonite® canister can lead to particulate contamination. This will eventually reduce volatile compound recovery, while making it more difficult to achieve EPA required blank levels. Entech’s Grab Samplers are a great solution to keep your canisters clean. The external filter allows rapid equilibration with the local environment to reduce net loss due to adsorption, and the “thimble” geometry provides the surface area required to quickly fill large canisters. All filters are Silonite® coated to maximize recovery of volatile chemicals.
Entech’s Restricted Samplers are identical to the Grab Samplers listed above, but also include a sapphire orifice to slow down sampling rates. Fill rates remain constant until the canister is half full. Sampling can be stopped at this point for a true time weighted sample or allowed to continue if a time-weighted average is not required. Approximate times for filling to 50% and 95% of atmospheric pressure are listed in the table below.