This ARP describes a gravimetric method for the determination of particulate contaminant in hydraulic fluids by the control filter technique.

NOTE: With this method, detectable contamination levels down to 0.2 mg (7.0 × 10^-6 ounces) per sample can be obtained with a standard deviation of ±0.1 mg (±3.5 × 10^-6 ounces).