Method and apparatus for pneumatically sampling powders

摘要

A pneumatic sampler for use in collecting a sample of xerographic toner from a mass of such toner. A positive-pressure air source is connected to atmosphere through a venturi so as to produce a negative-pressure source. The positive-pressure source is also adapted to be connected through a first conduit to the toner mass. Positive-pressure airflow through this first conduit both purges the first conduit of residual toner and fluidizes at least a portion of the toner mass. A toner sample container is adapted to be simultaneously connected through a second conduit to the venturi. The resulting negative-pressure airflow through the second conduit evacuates the container. Negative-pressure induced airflow also purges the second conduit of residual toner. The container is connected to the toner mass through the series-connected and now-purged first and second conduits, and the negative-pressure within the container produces flow of toner from the toner mass to the container.