1 This International Standard specifies a procedure for evaluating the pressure drop versus flow characteristics of in-dustrial oil hydraulic filters and provides a basis of agreement between the filter manufacturer and user.
2 Two standards of measurement are specified :
a) Class A — For accurate evaluation for referee purposes — requiring laboratory conditions.
b) Class B — For evaluation for general purposes — requiring test facilities less stringent that laboratory conditions.
3 This International Standard specifies the method of measuring the pressure drop across a hydraulic fluid filter under various conditions of flow.
DS/ISO 3968:1989 history
1989DS/ISO 3968:1989 Hydraulic fluid power. Filters. Evaluation of pressure drop versus flow characteristics