CONTAMINATION MEASUREMENT APPARATUS

摘要

A contamination measurement apparatus (10) for determining a level of particulate contamination in a fluid. The apparatus includes a filter (28) for passing a fluid therethrough. A volume indicator produces movement of a test piston (36) in response to the fluid passing through the filter (28). The flow decay characteristics of the fluid are determined in response to movement of the test piston (36). A back flush mechanism returns the fluid back through the filter (28) by use of a back flush piston (58) which reciprocates in a chamber (56) between a first position wherein the back flush piston (58) is engaged with the test piston (36), and a second position wherein the back flush piston (58) is disengaged from the test piston (36) so that the test piston (36) is free to move in response to the fluid volume.