Active Standard ASTM D7596 | Developed by Subcommittee: D02.96
Book of Standards Volume: 05.04
Significance and Use
This test method is intended for use in analytical laboratories including on-site in-service oil analysis laboratories. Periodic sampling and analysis of lubricants have long been used as a means to determine overall machinery health. Atomic emission spectroscopy (AES) is often employed for wear metal analysis (Test Methods D5185 and D6595). A number of physical property tests complement wear metal analysis and are used to provide information on lubricant condition (Test Methods D445, D2896, D6304, and D7279). Molecular spectroscopy (Practice E2412) provides direct information on molecular species of interest including additives, lubricant degradation products and contaminating fluids such as water, fuel and glycol. The direct imaging integrated tester provides complementary information on particle count, particle size, particle type, and soot content.
Particles in lubricating and hydraulic oils are detrimental because they increase wear, clog filters and accelerate oil degradation.
5.3 Particle count may aid in assessing the capability of a filtration system to clean the fluid, determine if off-line recirculating filtration is needed to clean the fluid, or aid in the decision whether or not to change the fluid.
5.4 An increase in the concentration and size of wear particles is indicative of incipient failure or component change out. Predictive maintenance by oil analysis monitors the concentration and size of wear particles on a periodic basis to predict failure.
5.5 High soot levels in diesel engine lubricating oil may indicate abnormal engine operation.
1.1 This test method covers the determination of particle concentration, particle size distribution, particle shape, and soot content for new and in-service oils used for lubrication and hydraulic systems by a direct imaging integrated tester.
1.1.1 The test method is applicable to petroleum and synthetic based fluids. Samples from 2 to 150 mm2/s at 40°C may be processed directly. Samples of greater viscosity may be processed after solvent dilution.
1.1.2 Particles measured are in the range from 4 μm to ≥ 70 μm with the upper limit dependent upon passing through a 100 μm mesh inlet screen.
1.1.3 Particle concentration measured may be as high as 5,000,000 particles per mL without significant coincidence error.
1.1.4 Particle shape is determined for particles greater than approximately 20 µm in length. Particles are categorized into the following categories: sliding, cutting, fatigue, nonmetallic, fibers, water droplets, and air bubbles.
1.1.5 Soot is determined up to approximately 1.5 % by weight.
1.1.6 This test method uses objects of known linear dimension for calibration.
1.2 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.
1.3 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.
2. Referenced Documents (purchase separately) The documents listed below are referenced within the subject standard but are not provided as part of the standard.
D445 Test Method for Kinematic Viscosity of Transparent and Opaque Liquids (and Calculation of Dynamic Viscosity)
D2896 Test Method for Base Number of Petroleum Products by Potentiometric Perchloric Acid Titration
D4057 Practice for Manual Sampling of Petroleum and Petroleum Products
D4175 Terminology Relating to Petroleum, Petroleum Products, and Lubricants
D4177 Practice for Automatic Sampling of Petroleum and Petroleum Products
D5185 Test Method for Determination of Additive Elements, Wear Metals, and Contaminants in Used Lubricating Oils and Determination of Selected Elements in Base Oils by Inductively Coupled Plasma Atomic Emission Spectrometry (ICP-AES)
D5967 Test Method for Evaluation of Diesel Engine Oils in T-8 Diesel Engine
D6304 Test Method for Determination of Water in Petroleum Products, Lubricating Oils, and Additives by Coulometric Karl Fischer Titration
D6595 Test Method for Determination of Wear Metals and Contaminants in Used Lubricating Oils or Used Hydraulic Fluids by Rotating Disc Electrode Atomic Emission Spectrometry
D7279 Test Method for Kinematic Viscosity of Transparent and Opaque Liquids by Automated Houillon Viscometer
E2412 Practice for Condition Monitoring of In-Service Lubricants by Trend Analysis Using Fourier Transform Infrared (FT-IR) Spectrometry
G40 Terminology Relating to Wear and Erosion
ISO StandardsISO4406 Hydraulic fluid power Fluids Method for coding level of contamination by solid particles
SAE StandardsSAEAS4059 Aerospace Fluid Power Cleanliness Classification for Hydraulic Fluids
ICS Number Code 75.100 (Lubricants, industrial oils and related products); 75.120 (Hydraulic fluids)