ASTM D8315-20

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.
Designation: D8315 − 20
Standard Test Method for
Determination of Wear Metals and Contamination Elements
in Used Industrial Oils by Sweeping Flat Electrode Atomic
Emission Spectrometry
This standard is issued under the fixed designation D8315; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. A
superscript epsilon (´) indicates an editorial change since the last revision or reapproval.
1. Scope Analytical results are particle size dependent and low results
may be obtained for those elements present in used oil samples
1.1 This test method covers the determination of wear
as large particles (referenced by Test Methods D5185 and
metals and contaminants in used industrial oils by sweeping
2 D6595).
flat electrode atomic emission spectroscopy (SFE-AES).
1.7 The values stated in SI units are to be regarded as
1.2 Industrial oil includes lubricant oil, gear box oil, hy-
standard. No other units of measurement are included in this
draulic fluid, compressor oil, turbine oil, synthetic oils, and
standard.
other petroleum oils.
1.8 This standard does not purport to address all of the
1.3 Methodworkingrangeforeveryelementisevaluatedby
safety concerns, if any, associated with its use. It is the
equations in 15.2.1 and tabulated in Table 6.
responsibility of the user of this standard to establish appro-
1.4 Though this technique is designed to analyze non-
priate safety, health, and environmental practices and deter-
suspended particles in lubricant samples, the precision state-
mine the applicability of regulatory limitations prior to use.
ments published here were established solely from homoge-
1.9 This international standard was developed in accor-
neous oil samples per Practice D6300 requirements. Non-
dance with internationally recognized principles on standard-
suspended particles, which are inhomogeneous by nature, were
ization established in the Decision on Principles for the
notsampledandevaluatedforderivingprecisionstatementsfor
Development of International Standards, Guides and Recom-
this test method (see Annex A1).
mendations issued by the World Trade Organization Technical
Barriers to Trade (TBT) Committee.
1.5 This test method provides a quick indication for abnor-
mal wear and the presence of contamination in new or used
2. Referenced Documents
industrial oils by immediately reporting:
2.1 ASTM Standards:
1.5.1 Normal fine particles of specific wear metals;
1.5.2 Non-suspendable particles of specific wear metals and D4057 Practice for Manual Sampling of Petroleum and
Petroleum Products
of contamination elements;
1.5.3 Less populated large particles (10 µm to 50 µm) of D4177 Practice for Automatic Sampling of Petroleum and
Petroleum Products
specific wear metals;
1.5.4 Contamination elements; and D5185 Test Method for Multielement Determination of
Used and Unused Lubricating Oils and Base Oils by
1.5.5 Additive elements.
Inductively Coupled Plasma Atomic Emission Spectrom-
1.6 This test method uses oil-soluble elements for calibra-
etry (ICP-AES)
tion and does not purport to relate quantitatively the values
D6300 Practice for Determination of Precision and Bias
determined as insoluble particles to the dissolved metals.
Data for Use in Test Methods for Petroleum Products,
Liquid Fuels, and Lubricants
This test method is under the jurisdiction of ASTM Committee D02 on D6595 Test Method for Determination of Wear Metals and
Petroleum Products, Liquid Fuels, and Lubricants and is the direct responsibility of
Contaminants in Used Lubricating Oils or Used Hydraulic
Subcommittee D02.03 on Elemental Analysis.
Fluids by Rotating Disc ElectrodeAtomic Emission Spec-
Current edition approved June 1, 2020. Published July 2020. DOI: 10.1520/
trometry
D8315-20.
The sole source of supply of the apparatus (COA Oil & Grease Analyzer and
accessories) known to the committee at this time is CYCP Oil Analyzers, LLC., 7
Beths Rd, Shrewsbury, MA01545, www.cycp-oilanalyzers.com. If you are aware of For referenced ASTM standards, visit the ASTM website, www.astm.org, or
alternative suppliers, please provide this information to ASTM International contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM
Headquarters.Your comments will receive careful consideration at a meeting of the Standards volume information, refer to the standard’s Document Summary page on
responsible technical committee, which you may attend. the ASTM website.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
D8315 − 20
3. Terminology D4057 and D4177; though the concentrations (in ppm) of
non-suspendable particles do not characterize the sizes of
3.1 Definitions:
particles, their values provide the partition of large and heavy
3.1.1 burn, vt—in emission spectroscopy, to vaporize and
particles against fine and small ones in fluid bulk.
excite a specimen with sufficient energy to generate spectral
3.2.9 sparking surface, n—the surface of a graphite flat
radiation.
electrode facing to a graphite rod electrode; on the surface test
3.1.2 calibration, n—the process by which the relationship
specimen is attached and spark is generated for vaporizing the
between signal intensity and elemental concentration is deter-
test specimen.
mined for a specific element analyzed.
3.2.10 standardization, n—the process of re-establishing
3.1.3 calibration curve, n—the graphical or mathematical
and correcting a calibration curve through the analysis of at
representation of a relationship between the assigned (known)
least two known oil standards.
values of standards and the measured responses from the
3.2.11 suspendable particles, n—wear metal and contami-
measurement system.
nation elements that are not oil-soluble but remain in suspen-
3.1.4 calibration standard, n—a standard having an ac-
sion in specific fluid bulk; suspendable particles might be
cepted value (reference value) for use in calibrating a measure-
captured by RDE-AES; they can be less assessed when oil
ment instrument or system.
sample is diluted by solvent; in most cases, suspendable
3.1.5 emission spectroscopy, n—measurement of energy
particles of wear metals are fine particles and come from
spectrum emitted by or from an object under some form of
normal wear of moving parts.
energetic stimulation; for example, light, electrical discharge,
3.2.12 sweeping arc discharge, n—the positions of two
and so forth.
counter electrodes have relative motion during arc discharge in
3.1.6 graphite disc electrode, n—a soft form of the element
order for test specimen on sparking surface to be burned
carbon manufactured into the shape of a disc for use as a
sequentially.
counter electrode in arc/spark spectrometers for oil analysis.
3.2.13 wear metal, n—material resulting from damage to a
3.2 Definitions of Terms Specific to This Standard:
solid surface due to relative motion between that surface and a
3.2.1 arc discharge, n—a self-sustaining, high current
contacting substance or substances; wear metal is not oil-
density, high temperature discharge, uniquely characterized by
soluble.
a cathode fall nearly equal to the ionization potential of the gas
3.2.14 XY sweeping table, n—a mechanical device for
or vapor in which it exists.
carrying the graphite flat electrode and moving the electrode
3.2.2 check sample, n—a reference material usually pre-
under the rod electrode in pre-programmed two horizontal
pared by a laboratory for its own use as a calibration standard,
dimensions (X and Y).
as a measurement control standard, or for the qualification of a
3.3 Abbreviations:
measurement method.
3.3.1 AES—Atomic Emission Spectroscopy
3.2.3 contamination element, n—material resulting from
contamination into an oil sample that may cause abnormal
4. Summary of Test Method
wear or lubricant degradation.
4.1 A used oil test specimen is placed on the sparking
3.2.4 counter electrode, n—eitheroftwographiteelectrodes
surface of a XY-movable (sweep-able) graphite flat electrode.
in an atomic emission spectrometer across which an arc or
Agraphite rod electrode directs arc discharge to a point on the
spark is generated.
flat electrode surface. Evaporation and excitation of the speci-
3.2.5 graphite flat electrode, n—a soft form of the element
men is implemented with controlled XY-motion of the flat
carbon manufactured to possess a flat surface for use as both
electrode. The radiant energies of selected analytical lines at
holding oil test specimen and a counter electrode in arc/spark
each point of the sparking surface are collected by a photon
spectrometers for oil analysis.
collection device and stored into computer memory.
3.2.6 graphite rod electrode, n—a soft form of the element
4.2 In one test mode test fluid is well disturbed and the
carbon manufactured into the shape of a rod for use as a
non-suspendable particles and the suspended particles are
counter electrode in arc/spark spectrometers for oil analysis.
introduced onto spark gap. The test result represents total
concentration of particles in the fluid bulk. In the second test
3.2.7 less populated large particles, n—wear metal particles
mode, the fluid undergoes settling. Because the fluid is intro-
that cause emission intensity surges against most populated
duced to the spark gap by pouring it down, only the top part of
particles or background in SFE-AES test; whether they are
thefluid,whichonlycontainssuspendableparticles,issparked.
suspendabledependsonbothspecificphysicalpropertiesofthe
The second test result represents the concentration of suspend-
particles and of oil fluid.
able particles. The concentration of non-suspended particles
3.2.8 non-suspendable particles, n—wear metal and con-
can be calculated by finding the difference of two tests of the
tamination elements that are not oil soluble and cannot remain
same test fluid.
in suspension without disturbance in a specific fluid sample.
Non suspendable particles are always in suspension under 4.3 In one mode the measured concentrations from all
working conditions of machinery and can be collected into a points of the sparking surface can be combined into one
fluid sample via sampling practices described by Practices average concentration for the element in the entire area. In a
D8315 − 20
second mode of analysis each reading is considered separately 6.4 Less Populated Particles—If large particles are not on
with the understanding that each spark is analyzing a different the route of sparking, they will not be detected and reported.
area of an inhomogeneous sample. With either numerical or Ontheotherhand,falseresultsmaybereportedifalotofsmall
graphical analysis an understanding of the particle size and particles are aggregated either spatially or by bonded forces, or
distribution in the sampled area can be obtained in this second both.
mode.
6.5 Poor Maintenance—Because test specimen is burned in
the sparking chamber, ashes and combustion residuals can be
5. Significance and Use
adsorbed or deposited everywhere in the chamber. Dry paper
tissues can be used to clean the chamber surfaces in order to
5.1 Used Industrial Oil—The detection of large particles are
important inputs for used industrial lubricant condition morni- maintain the instrument in a good and operable condition.
Particular attention should be paid to the groove of the rod
toring. For wear metals, these particles, in size, are represented
by those between 20 µm and 50 µm in engine oil, 80 µm or electrode holder, the lens, and the fixture of flat electrode,
which shall be cleaned on a daily basis. Also, the fixture of
greater in gear-box oil. In desert or windy areas, large sand and
graphite flat electrode shall be cleaned after every sample.
dustparticlescanenterin-servicelubricant.Theconcentrations
contributed from large particles can be more sensitive to
6.6 Viscosity Effects—Differences in viscosity of used oil
serious or catastrophic failure of industrial equipment than
samples will cause differences in sample film thickness on the
those from 10 µm or less. In spectroscopic analysis, excluding
flat electrode. Internal references of the instrument will com-
large particles significantly under-reports the concentrations of
pensateforaportionofthedifferences.Inusedoilapplications,
wear and contamination elements. The corresponding results
the hydrogen 486.10 nm spectral line has become the industry
may not represent the actual state of in-service lubricant.
standard for use as an internal reference. Without a reference,
Because this test method posts less limitation on the size of
trendeddataonusedoilwillbeadverselyaffectedifthesample
wear metal particles while still reporting normal fine wear
base stock has a different viscosity from the base line samples
particles, it provides a means to assess wear and contamination
(referenced by Test Method D6595).
elements in a comprehensive range of the size of particulates
and raises the fidelity of spectroscopic analysis of in-service
7. Apparatus
lubricant.
7.1 Electrode Sharpener—An electrode sharpener is neces-
5.2 Non-suspendable Particles in Used Industrial Oil—The
sary to remove the contaminated portion of the rod electrode
increase of non-suspendable particles suggests excessive wear remainingfromthepreviousdetermination.Italsoformsanew
or poor sealing of machinery, or both. Large amounts of such
160° angle on the end of the electrode. Electrode sharpeners
particulate in industrial oil bulk itself are harmful to moving are not required for instruments using a pre-shaped disc
partsofmachinery.Thistestmethodprovidesanothermeansto
electrode as the counter electrode.
identify the presence or absence of the non-suspendable
7.2 Sweeping Flat ElectrodeAtomic Emission Spectrometer,
particles for machinery condition monitoring.
a simultaneous spectrometer consisting of an excitation source
(which uses a graphite flat electrode lying on an XY sweeping
6. Interferences
table), polychromator optics and a readout system. Suggested
6.1 Spectral—Most spectral interferences can be avoided by elements and wavelengths are listed in Table 1. When multiple
judicious choice of spectral lines. High concentrations of
wavelengths are listed, they are in the order of preference or
additive elements can have an interfering influence on the desired analytical range.
spectral lines used for determining wear metals (referenced by
Test Methods D5185 and D6595). Instrument manufacturers
usually compensate for spectral interferences during factory The method and apparatus for emission spectroscopy utilizing a flat plate for
sample holding and excitation is covered by a patent (U.S. Patent #8559004).
calibration. A background correction system, which subtracts
Interested parties are invited to submit information regarding the identification of an
unwanted intensities on either side of the spectral line, shall
alternative(s) to this patented item to the ASTM International Headquarters. Your
also be used for this purpose. When spectral interferences
comments will receive careful consideration at a meeting of the responsible
technical committee, which you may attend.
cannot be avoided with spectral line selection and background
correction, the necessary corrections shall be made using the
TABLE 1 Elements and Recommended Wavelengths
computer software supplied by the instrument manufacturer.
Element Wavelength, nm Element Wavelength, nm
6.2 Particulate—When large particles are detected, the ana-
Aluminum 308.21 Nickel 341.48
lytical results will be lower than the actual concentration they
Barium 230.48, 455.40 Phosphorus 255.32, 214.91
Boron 249.67 Potassium 766.49
represent. Large particles may not be fully vaporized by the
Calcium 393.37, 445.48 Silicon 251.60
spark (referenced by Test Methods D5185 and D6595).
Chromium 425.43 Silver 328.07, 243.78
Copper 324.75, 224.26 Sodium 588.89, 589.59
6.3 Particle Suspension—Large particles can only remain in
Iron 259.94 Tin 317.51
suspension for a short time after vibration, depending on the
Lead 283.31 Titanium 334.94
viscosity of test specimen. Wear metal and contamination Lithium 670.78 Tungsten 400.87
Manganese 403.07, 294.92 Vanadium 290.88, 437.92
elements would be significantly under-reported if the test
Magnesium 280.20, 518.36 Zinc 213.86
specimen is not mixed thoroughly immediately before it is
Molybdenum 281.60
poured down to sparking surface.
D8315 − 20
8. Reagents and Materials sentative of the samples of interest. These QC samples can be
used to check the validity of the testing process as described in
8.1 Base Oil, a 75 cSt base oil free of analyte to be used as
Section 13.
a calibration blank or for blending calibration standards, or
both.
9. Hazards
8.2 Check Samples, an oil standard or sample of known
9.1 Used oil can contain hazardous material from compo-
concentration which is periodically analyzed as a go/no go
nent source or the contamination process, or both. Follow
sample to confirm the need for standardization based on an
applicable regulations and procedures when disposing of used
allowable 10 % accuracy limit.
oil.
8.3 Cleaning Solution, an environmentally safe,
9.2 Incorrect installation of counter electrodes can cause
nonchlorinated, rapid evaporating, and non-film producing
damage of arc discharge system. Follow instructions of the
solvent, to remove spilled or splashed oil sample in the s
...