NIST Traceable Particle Counter Calibration Standard - Contamination Control Enters the Next Century

Liquid automatic optical particle counters (APCs) are used to monitor contamination levels in hydraulic and engine oil, to establish component and assembly cleanliness level specifications, and to determine filter efficiencies and size ratings. As a result of the recent revisions to ISO particle counter calibration, multi-pass filter test, and on-line particle counter calibration standards, it is anticipated that the quality and reliability of particle count and filter test data will improve, increasing their usefulness to the hydraulics, automotive and aerospace industries. However, the resultant redefinition of particle sizes affects how contamination levels and filter performance are reported and interpreted. The impact of these changes is discussed in this report.