Abstract: Apparatus (20) for testing the extent of contaminants in a fluid during a test period, comprises: a source (Ps) of pressurized fluid to be tested; a fluid sump (R); a first flow restriction (R1) adapted to be supplied with fluid flow from the source, the first flow restriction being configured as an annular clearance between a first land (24) and a first bore (22) and being sized and arranged so as to be progressively occluded by contaminants in the fluid flow during said test period; a second flow restriction (R2) arranged between the first flow restriction and said sump, the second flow restriction being configured as an annular clearance between a second land (25) and a second bore (22), the second flow restriction being substantially the same dimensionally as the first flow restriction so that the second flow restriction will not be occluded by contaminants passing through the first flow restriction and the pressure drops across each of the flow restrictions will be substantially equal at the beginning of

Abstract: The invention provides an improvement in apparatus (20) for testing the level of contaminants in a fluid during a test period. The apparatus has a source of pressurized fluid (Ps) to be tested; a fluid sump (R); and a test passage (48) which is substantially free of occluding contaminants at the beginning of the test period and which is adapted to be supplied with a flow of fluid from the source. The passage is so configured and arranged as to be progressively occluded by contaminants in the fluid flow. The apparatus also includes a device (23) defining a variable-volume chamber (47). The volume of said chamber is variable between a minimum value and a maximum value.

Abstract: Apparatus (20) for testing the extent of contaminants in a fluid during a test period, comprises: a source (Ps) of pressurized fluid to be tested; a fluid sump (R); a first flow restriction (R1) adapted to be supplied with fluid flow from the source, the first flow restriction being configured as an annular clearance between a first land (24) and a first bore (22) and being sized and arranged so as to be progressively occluded by contaminants in the fluid flow during said test period; a second flow restriction (R2) arranged between the first flow restriction and said sump, the second flow restriction being configured as an annular clearance between a second land (55) and a second bore (22), the second flow restriction being substantially the same dimensionally as the first flow restriction so that the second flow restriction will not be occluded by contaminants passing through the first flow restriction and the pressure drops across each of the flow restrictions will be substantially equal at the beginning of

Abstract: The invention provides an improvement in apparatus (20) for testing the level of contaminants in a fluid during a test period. The apparatus has a source of pressurized fluid (Ps) to be tested; a fluid sump (R); and a test passage (48) which is substantially free of occluding contaminants at the beginning of the test period and which is adapted to be supplied with a flow of fluid from the source. The passage is so configured and arranged as to be progressively occluded by contaminants in the fluid flow. The apparatus also includes a device (23) defining a variable-volume chamber (47). The volume of said chamber is variable between a minimum value and a maximum value.