The multi pass test stand is mainly used for testing the performance of hydraulic filters according to ISO 19438, ISO 4548-12 and ISO 16889 standards. These standards describe a method for determining the contaminant capacity, particle removal and differential pressure characteristics of filter elements. In order to determine such characteristics, filter elements are injected with continuous contaminant (test dust), whereas online particle sensors measure the contamination, thus making the evaluation of the filter element’s performance possible.