5.1 Used Lubricating Oil—The determination of debris in used oil is a key diagnostic method practiced in machine condition monitoring programs. The presence or increase in concentration of specific wear metals can be indicative of the early stages of wear if there are baseline concentration data for comparison. A marked increase in contaminant elements can be indicative of foreign materials in the lubricants, such as antifreeze or sand, which may lead to wear or lubricant degradation. The test method identifies the metals and their concentration so that trends relative to time or distance can be established and corrective action can be taken prior to more serious or catastrophic failure.

1.1 This test method covers the determination of wear metals and contaminants in used lubricating oils and used hydraulic fluids by rotating disc electrode atomic emission spectroscopy (RDE-AES).

1.2 This test method provides a quick indication for abnormal wear and the presence of contamination in new or used lubricants and hydraulic fluids.

1.3 This test method uses oil-soluble metals for calibration and does not purport to relate quantitatively the values determined as insoluble particles to the dissolved metals. Analytical results are particle size dependent and low results may be obtained for those elements present in used oil samples as large particles.

1.4 The test method is capable of detecting and quantifying elements resulting from wear and contamination ranging from dissolved materials to particles approximately 10 μm in size.

1.5 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.

1.5.1 The preferred units are mg/kg (ppm by mass).

1.6 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.

1.7 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.