ASTM D7483-21

Standard Test Method for Determination of Dynamic Viscosity and Derived Kinematic Viscosity of Liquids by Oscillating Piston Viscometer

SIGNIFICANCE AND USE
5.1 Many petroleum products, as well as non-petroleum materials, are used as lubricants for bearings, gears, compressor cylinders, hydraulic equipment, etc. Proper operation of this equipment depends upon the viscosity of these liquids.  
5.2 Oscillating piston viscometers allow viscosity measurement of a broad range of materials including transparent, translucent and opaque liquids. The measurement principle and stainless steel construction makes the Oscillating Piston Viscometer resistant to damage and suitable for portable operations. The measurement itself is automatic and does not require an operator to time the oscillation of the piston. The electromagnetically driven piston mixes the sample while under test. The instrument requires a sample volume of less than 5 mL and typical solvent volume of less than 10 mL which minimizes cleanup effort and waste.
SCOPE
1.1 This test method covers the measurement of dynamic viscosity and derivation of kinematic viscosity of liquids, such as new and in-service lubricating oils, by means of an oscillating piston viscometer.  
1.2 This test method is applicable to Newtonian and non-Newtonian liquids; however the precision statement was developed using Newtonian liquids.  
1.3 The range of dynamic viscosity covered by this test method is from 0.2 mPa·s to 20 000 mPa·s (which is approximately the kinematic viscosity range of 0.2 mm2/s to 22 000 mm2/s for new oils) in the temperature range between –40 °C to 190 °C; however the precision has been determined only for new and used oils in the range of 34 mPa·s to 1150 mPa·s at 40 °C, 5.7 mPa·s to 131 mPa·s at 100 °C, and 46.5 mm2/s to 436 mm2/s at 40 °C.  
1.4 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.  
1.5 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, health, and environmental practices and determine the applicability of regulatory limitations prior to use.  
1.6 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.

General Information

• Status: Published
• Publication Date: 31-Dec-2020
• ICS: 17.060 - Measurement of volume, mass, density, viscosity
• Technical Committee: D02 - Petroleum Products, Liquid Fuels, and Lubricants
• Drafting Committee: D02.07 - Flow Properties

Relations

• Refers: ASTM D445-24 - Standard Test Method for Kinematic Viscosity of Transparent and Opaque Liquids (and Calculation of Dynamic Viscosity)
• Effective Date: 01-Apr-2024
• Refers: ASTM D6300-24 - Standard Practice for Determination of Precision and Bias Data for Use in Test Methods for Petroleum Products, Liquid Fuels, and Lubricants
• Effective Date: 01-Mar-2024
• Refers: ASTM D6708-24 - Standard Practice for Statistical Assessment and Improvement of Expected Agreement Between Two Test Methods that Purport to Measure the Same Property of a Material
• Effective Date: 01-Mar-2024
• Refers: ASTM D6300-23a - Standard Practice for Determination of Precision and Bias Data for Use in Test Methods for Petroleum Products, Liquid Fuels, and Lubricants
• Effective Date: 01-Dec-2023
• Refers: ASTM D445-23 - Standard Test Method for Kinematic Viscosity of Transparent and Opaque Liquids (and Calculation of Dynamic Viscosity)
• Effective Date: 01-Nov-2023
• Refers: ASTM D6792-23c - Standard Practice for Quality Management Systems in Petroleum Products, Liquid Fuels, and Lubricants Testing Laboratories
• Effective Date: 01-Nov-2023
• Refers: ASTM D6792-23b - Standard Practice for Quality Management Systems in Petroleum Products, Liquid Fuels, and Lubricants Testing Laboratories
• Effective Date: 01-Oct-2023
• Refers: ASTM D6300-19a - Standard Practice for Determination of Precision and Bias Data for Use in Test Methods for Petroleum Products and Lubricants
• Effective Date: 01-Dec-2019
• Refers: ASTM D6708-19 - Standard Practice for Statistical Assessment and Improvement of Expected Agreement Between Two Test Methods that Purport to Measure the Same Property of a Material
• Effective Date: 01-May-2019
• Refers: ASTM D6708-18 - Standard Practice for Statistical Assessment and Improvement of Expected Agreement Between Two Test Methods that Purport to Measure the Same Property of a Material
• Effective Date: 01-Apr-2018
• Refers: ASTM D5967-17 - Standard Test Method for Evaluation of Diesel Engine Oils in T-8 Diesel Engine
• Effective Date: 01-May-2017
• Refers: ASTM D445-16 - Standard Test Method for Kinematic Viscosity of Transparent and Opaque Liquids (and Calculation of Dynamic Viscosity)
• Effective Date: 15-Dec-2016
• Refers: ASTM D6708-16a - Standard Practice for Statistical Assessment and Improvement of Expected Agreement Between Two Test Methods that Purport to Measure the Same Property of a Material
• Effective Date: 01-Apr-2016
• Refers: ASTM D6300-16 - Standard Practice for Determination of Precision and Bias Data for Use in Test Methods for Petroleum Products and Lubricants
• Effective Date: 01-Apr-2016
• Refers: ASTM D6708-16 - Standard Practice for Statistical Assessment and Improvement of Expected Agreement Between Two Test Methods that Purport to Measure the Same Property of a Material
• Effective Date: 01-Jan-2016

Overview

ASTM D7483-21 is the Standard Test Method for Determination of Dynamic Viscosity and Derived Kinematic Viscosity of Liquids by Oscillating Piston Viscometer. Developed by ASTM International, this standard outlines procedures to measure the viscosity of various liquids, including both new and in-service lubricating oils, using the oscillating piston viscometer technique. Viscosity is a critical property for fluids used in bearings, gears, compressors, hydraulic equipment, and other machinery. Accurate viscosity measurement ensures proper equipment performance, reduces wear, and supports quality assurance in manufacturing and maintenance.

The oscillating piston viscometer offers significant versatility, being applicable to a wide range of liquids - including transparent, translucent, and opaque fluids. The device features automatic operation, robust stainless steel construction, and requires minimal sample and solvent quantities, making it highly efficient and suitable for both laboratory and portable field use.

Key Topics

• Measurement Principle: Utilizes an electromagnetically driven piston oscillating within a thermally controlled measurement chamber to determine dynamic viscosity. Kinematic viscosity is then derived from dynamic viscosity and liquid density.
• Sample Requirements: Typically less than 5 mL of sample and less than 10 mL of solvent, minimizing waste and facilitating simple cleanup.
• Applicability: Suitable for both Newtonian and non-Newtonian liquids; however, precision data was mainly developed from Newtonian fluids.
• Operational Range:
  • Dynamic viscosity: 0.2 mPa·s to 20,000 mPa·s
  • Kinematic viscosity (approximate): 0.2 mm²/s to 22,000 mm²/s
  • Temperature: –40 °C to 190 °C
• Automation and Safety: Measurement is automatic with no need for manual timing. The method emphasizes establishment of appropriate safety, health, and environmental practices.

Applications

The ASTM D7483-21 test method offers significant practical value across multiple industries where precision lubrication and fluid performance are essential. Common application areas include:

• Lubricant Formulation and Quality Control: Ensures correct dynamic and kinematic viscosity of lubricants used in automotive, industrial, and marine engines.
• Hydraulic Fluids: Provides vital data to maintain system efficiency and prevent equipment failure in hydraulic machinery and equipment.
• Petroleum Product Analysis: Supports the analysis of both new and used oils, contributing to performance monitoring and maintenance scheduling.
• Field Testing and Research: The viscometer’s robustness and portability enable use in field conditions as well as research laboratories for rapid and reliable viscosity measurements.
• Process Optimization: Assists in continuous monitoring and optimization of processes that depend on fluid properties.

Related Standards

Several standards complement ASTM D7483-21 to provide a comprehensive quality assurance framework for viscosity measurements:

• ASTM D445 - Test Method for Kinematic Viscosity of Transparent and Opaque Liquids (and Calculation of Dynamic Viscosity)
• ASTM D2162 - Practice for Basic Calibration of Master Viscometers and Viscosity Oil Standards
• ASTM D4057 / D4177 - Practices for Manual and Automatic Sampling of Petroleum and Petroleum Products
• ASTM D6792 - Practice for Quality Management Systems in Petroleum Products, Liquid Fuels, and Lubricants Testing Laboratories
• ISO/IEC 17025 - General Requirements for the Competence of Testing and Calibration Laboratories
• NIST Technical Note 1297 - Guideline for Evaluating and Expressing the Uncertainty of NIST Measurement Results

Summary

ASTM D7483-21 provides a robust, efficient, and precise method for measuring dynamic and kinematic viscosity using an oscillating piston viscometer. Its wide measurement range, minimal sample requirements, and suitability for diverse liquid types make it an essential standard for industries where fluid properties affect performance and reliability. Adherence to this test method supports regulatory compliance, operational excellence, and product quality.

Keywords: ASTM D7483-21, dynamic viscosity, kinematic viscosity, oscillating piston viscometer, lubricating oil, fluid testing, quality control, viscosity measurement.

Standards Content (Sample)

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: D7483 − 21
Standard Test Method for
Determination of Dynamic Viscosity and Derived Kinematic
Viscosity of Liquids by Oscillating Piston Viscometer
This standard is issued under the fixed designation D7483; 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* 2. Referenced Documents
2.1 ASTM Standards:
1.1 This test method covers the measurement of dynamic
D445 Test Method for Kinematic Viscosity of Transparent
viscosity and derivation of kinematic viscosity of liquids, such
and Opaque Liquids (and Calculation of Dynamic Viscos-
as new and in-service lubricating oils, by means of an
ity)
oscillating piston viscometer.
D2162 Practice for Basic Calibration of Master Viscometers
1.2 This test method is applicable to Newtonian and non-
and Viscosity Oil Standards
Newtonian liquids; however the precision statement was de-
D4057 Practice for Manual Sampling of Petroleum and
veloped using Newtonian liquids.
Petroleum Products
D4177 Practice for Automatic Sampling of Petroleum and
1.3 The range of dynamic viscosity covered by this test
Petroleum Products
method is from 0.2 mPa·s to 20 000 mPa·s (which is approxi-
D5967 Test Method for Evaluation of Diesel Engine Oils in
mately the kinematic viscosity range of 0.2 mm /s to
T-8 Diesel Engine
22 000 mm /s for new oils) in the temperature range between
D6300 Practice for Determination of Precision and Bias
–40 °C to 190 °C; however the precision has been determined
Data for Use in Test Methods for Petroleum Products,
only for new and used oils in the range of 34 mPa·s to
Liquid Fuels, and Lubricants
1150 mPa·s at 40 °C, 5.7 mPa·s to 131 mPa·s at 100 °C, and
2 2
D6708 Practice for StatisticalAssessment and Improvement
46.5 mm /s to 436 mm /s at 40 °C.
of Expected Agreement Between Two Test Methods that
1.4 The values stated in SI units are to be regarded as
Purport to Measure the Same Property of a Material
standard. No other units of measurement are included in this
D6792 Practice for Quality Management Systems in Petro-
standard.
leum Products, Liquid Fuels, and Lubricants Testing
Laboratories
1.5 This standard does not purport to address all of the
2.2 ISO Standards:
safety concerns, if any, associated with its use. It is the
ISO/EC 17025 General Requirements for the Competence
responsibility of the user of this standard to establish appro-
of Testing and Calibration Laboratories
priate safety, health, and environmental practices and deter-
2.3 NIST Standard:
mine the applicability of regulatory limitations prior to use.
NIST Technical Note 1297 Guideline for Evaluating and
1.6 This international standard was developed in accor-
Expressing the Uncertainty of NISTMeasurement Results
dance with internationally recognized principles on standard-
ization established in the Decision on Principles for the
3. Terminology
Development of International Standards, Guides and Recom-
3.1 Definitions:
mendations issued by the World Trade Organization Technical
3.1.1 density, n—mass per unit volume.
Barriers to Trade (TBT) Committee.
For referenced ASTM standards, visit the ASTM website, www.astm.org, or
contact ASTM Customer Service at [e-mail]. For Annual Book of ASTM
This test method is under the jurisdiction of ASTM Committee D02 on Standards volume information, refer to the standard’s Document Summary page on
Petroleum Products, Liquid Fuels, and Lubricants and is the direct responsibility of the ASTM website.
Subcommittee D02.07 on Flow Properties. Available from International Organization for Standardization (ISO), 1, ch. de
Current edition approved Jan. 1, 2021. Published January 2021. Originally la Voie-Creuse, Case postale 56, CH-1211, Geneva 20, Switzerland, http://
approved in 2008. Last previous edition approved in 2020 as D7483 – 20a. DOI: www.iso.ch.
10.1520/D7483-21. Available from http://physics.nist.gov/ccu/Uncertainty/index.html.
*A Summary of Changes section appears at the end of this standard
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
D7483 − 21
FIG. 1 Viscometer with Electronics
3.1.2 dynamic viscosity (η), n—theratiobetweentheapplied travel times. This information is then applied to a calibration
shear stress and rate of shear of a liquid at a given temperature. curveusingliquidsofknownviscositytocalculatethedynamic
3.1.2.1 Discussion—It is sometimes called the coefficient of viscosity. The kinematic viscosity is derived by an externally
dynamic viscosity or, simply, viscosity. Thus, dynamic viscos- measured density by additionally measuring the ratio between
ity is a measure of the resistance to flow or to deformation of the up and down travel times. The precision and bias data for
a liquid under external shear forces. kinematic viscosity (as published in RR:D02-1755 ) were
3.1.2.2 Discussion—Thetermdynamicviscositycanalsobe derived by externally measured density and do not apply to the
used in a different context to denote a frequency-dependent internal density measurement.
quantity in which shear stress and shear rate have a sinusoidal
5. Significance and Use
time dependence.
5.1 Many petroleum products, as well as non-petroleum
3.1.3 kinematic viscosity, n—the ratio of the dynamic vis-
materials, are used as lubricants for bearings, gears, compres-
cosity (η) to the density (ρ) of a liquid at a given temperature.
sor cylinders, hydraulic equipment, etc. Proper operation of
3.1.3.1 Discussion—For gravity flow under a given hydro-
this equipment depends upon the viscosity of these liquids.
static head, the pressure head of a liquid is proportional to its
density, (ρ). Therefore, the kinematic viscosity, (ν), is a
5.2 Oscillating piston viscometers allow viscosity measure-
measure of the resistance to flow of a liquid under gravity.
ment of a broad range of materials including transparent,
translucentandopaqueliquids.Themeasurementprincipleand
3.1.4 rate of shear (shear rate), n—in liquid flow, the
stainless steel construction makes the Oscillating Piston Vis-
velocity gradient across the liquid.
cometer resistant to damage and suitable for portable opera-
3.1.5 shear stress, n—the force per unit area in the direction
tions.Themeasurementitselfisautomaticanddoesnotrequire
of the flow.
an operator to time the oscillation of the piston. The electro-
3.1.5.1 Discussion—TheSIunitforshearstressisthepascal
magnetically driven piston mixes the sample while under test.
(Pa).
Theinstrumentrequiresasamplevolumeoflessthan5 mLand
3.2 Definitions of Terms Specific to This Standard:
typical solvent volume of less than 10 mL which minimizes
3.2.1 oscillating piston viscometer, n—a device that mea-
cleanup effort and waste.
sures the travel time of a piston driven electromagnetically into
stationary oscillating motion through a liquid at a controlled
6. Apparatus
force in order to determine the dynamic viscosity of the liquid. 6,7
6.1 Oscillating Piston Viscometer:
4. Summary of Test Method
Supporting data have been filed at ASTM International Headquarters and may
4.1 A specimen of sample is placed in the thermally
beobtainedbyrequestingResearchReportRR:D02-1755.ContactASTMCustomer
controlled measurement chamber where the piston resides.The
Service at [e-mail].
pistonisdrivenintooscillatorymotionwithinthemeasurement 6
The Oscillating Piston Viscometer is covered by a patent. Interested parties are
invited to submit information regarding the identification of an alternative to this
chamber by a controlled magnetic field. Once the sample is at
patented item to theASTM International headquarters. Your comments will receive
thetesttemperature,asdeterminedbythetemperaturedetector,
careful consideration at a meeting of the responsible technical committee, which
the piston is propelled repeatedly through the liquid (by the
you may attend.
magnetic field).Ashear stress (ranging from 5 Pa to 750 Pa) is
The sole sources of supply for the apparatus known to the committee at this
time is Cambridge Viscosity Inc., 101 Station Landing, Medford, MA 02155
imposed on the liquid under test due to the piston travel. The
(www.cambridgeviscosity.com). If you are aware of alternative suppliers, please
dynamic viscosity is determined by measuring the average
provide this information toASTM International Headquarters. Your comments will
travel time of the piston. The kinematic viscosity is derived by
receive careful consideration at a meeting of the responsible technical committee,
additionally measuring the ratio between the up and down which you may attend.
D7483 − 21
TABLE 1 Viscosity Ranges of Oscillating Viscometer Pistons
Minimum Viscosity (mPa·s ) Maximum Viscosity (mPa·s ) Piston Designation Nominal Piston Diameter (mm) Recommended Sample Volume
(mL)
0.02 2 SP20 7.87 3.2–5
0.25 5 SP50 7.83 3.2–5
0.5 10 SP11 7.81 3.2–5
1 20 SP21 7.76 3.5–5
2.5 50 SP51 7.68 3.5–5
5 100 SP12 7.62 3.5–5
10 200 SP22 7.54 3.5–5
25 500 SP52 7.34 3.5–5
50 1000 SP13 7.21 4.0–5
100 2000 SP23 6.96 4.0–5
250 5000 SP53 6.27 4.0–5
500 10 000 SP14 6.05 4.0–5
1000 20 000 SP24 5.72 4.0–5
6.1.1 The oscillating piston viscometer (see Fig. 1) com- dards shall be traceable to master viscometer procedures
prises a measurement chamber and calibrated piston capable of described in Practice D2162.
measuring the dynamic viscosity within the limits of precision
7.2 The uncertainty of the certified viscosity reference
given in Section 16.
standard shall be stated for each certified value (k = 2, 95 %
6.1.2 Piston—Free moving, magnetically driven body
confidence). See ISO/EC 17025 or NIST TN 1297.
within a Oscillating Piston Viscometer which is used for
7.2.1 The certified viscosity reference should have a pub-
measuring the viscosity of liquids. Individual pistons are sized
lished viscosity in accordance with Test Method D445 or
to measure specific viscosity ranges by varying the sensor
equivalent means that is close to that of the liquids being tested
annulus. See Table 1 for the selection of the piston according
at the test temperature. For example, if intended measurements
to the viscosity range.
are to be made from 5 mPa·s to 25 mPa·s at 100 °C, then a
6.1.3 Measurement Chamber—Location within Oscillating
reference oil viscosity of 15 mPa·s at 100 °C would be appro-
Piston Viscometer where piston motion (through the liquid
priate.
under test) occurs due to an imposed electromagnetic field. See
7.3 Cleaning solvents miscible with the sample and chemi-
Fig. 2.
cally compatible with the wetted viscometer components (such
6.1.4 Electronics—Capable of controlling the electromag-
as alcohols, toluene, etc.). These wetted components are
neticfieldtopropelanddetectthetraveltimeofthepistonwith
typically 316L and 430 Stainless Steel.
a discrimination of 0.01 s or better and uncertainty within
60.07 %. The travel time is calibrated to be between 0.4 s and 7.4 Quality control (QC) liquid similar to 7.1, but with
60 s, at a distance of 5 mm.
viscosity values internally certified as noted in 12.2.
6.1.5 Temperature Controlled Jacket—Sufficient for main-
8. Sampling, Samples, and Test Units
taining measurement chamber temperature within 60.06 °C.
6.1.6 Temperature Measuring Device—Industrial platinum
8.1 Ensurethatthesampleishomogenous.Enginesampling
resistance thermometer (
...

This document is not an ASTM standard and is intended only to provide the user of an ASTM standard an indication of what changes have been made to the previous version. Because
it may not be technically possible to adequately depict all changes accurately, ASTM recommends that users consult prior editions as appropriate. In all cases only the current version
of the standard as published by ASTM is to be considered the official document.
Designation: D7483 − 20a D7483 − 21
Standard Test Method for
Determination of Dynamic Viscosity and Derived Kinematic
Viscosity of Liquids by Oscillating Piston Viscometer
This standard is issued under the fixed designation D7483; 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*
1.1 This test method covers the measurement of dynamic viscosity and derivation of kinematic viscosity of liquids, such as new
and in-service lubricating oils, by means of an oscillating piston viscometer.
1.2 This test method is applicable to Newtonian and non-Newtonian liquids; however the precision statement was developed using
Newtonian liquids.
1.3 The range of dynamic viscosity covered by this test method is from 0.2 mPa·s to 20 000 mPa·s (which is approximately the
2 2
kinematic viscosity range of 0.2 mm /s to 22 000 mm /s for new oils) in the temperature range between –40 °C to 190 °C; however
the precision has been determined only for new and used oils in the range of 34 mPa·s to 1150 mPa·s at 40 °C, 5.7 mPa·s to
2 2
131 mPa·s at 100 °C, and 46.5 mm /s to 436 mm /s at 40 °C.
1.4 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.
1.5 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, health, and environmental practices and determine the applicability of
regulatory limitations prior to use.
1.6 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.
2. Referenced Documents
2.1 ASTM Standards:
D445 Test Method for Kinematic Viscosity of Transparent and Opaque Liquids (and Calculation of Dynamic Viscosity)
D2162 Practice for Basic Calibration of Master Viscometers and Viscosity Oil Standards
D4057 Practice for Manual Sampling of Petroleum and Petroleum Products
D4177 Practice for Automatic Sampling of Petroleum and Petroleum Products
D5967 Test Method for Evaluation of Diesel Engine Oils in T-8 Diesel Engine
D6300 Practice for Determination of Precision and Bias 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 Petroleum Products, Liquid Fuels, and Lubricants and is the direct responsibility of Subcommittee
D02.07 on Flow Properties.
Current edition approved Sept. 1, 2020Jan. 1, 2021. Published October 2020January 2021. Originally approved in 2008. Last previous edition approved in 2020 as
D7483 – 20.D7483 – 20a. DOI: 10.1520/D7483-20A.10.1520/D7483-21.
For referenced ASTM standards, visit the ASTM website, www.astm.org, or contact ASTM Customer Service at [e-mail]. For Annual Book of ASTM Standards
volume information, refer to the standard’s Document Summary page on the ASTM website.
*A Summary of Changes section appears at the end of this standard
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
D7483 − 21
D6708 Practice for Statistical Assessment and Improvement of Expected Agreement Between Two Test Methods that Purport
to Measure the Same Property of a Material
D6792 Practice for Quality Management Systems in Petroleum Products, Liquid Fuels, and Lubricants Testing Laboratories
2.2 ISO Standards:
ISO/EC 17025 General Requirements for the Competence of Testing and Calibration Laboratories
2.3 NIST Standard:
NIST Technical Note 1297 Guideline for Evaluating and Expressing the Uncertainty of NIST Measurement Results
3. Terminology
3.1 Definitions:
3.1.1 density, n—mass per unit volume at a specified temperature.volume.
3.1.1.1 Discussion—
For common fuel and lubricant applications, density at atmospheric pressure is assumed. However, high pressure can impact
density.
3.1.2 dynamic viscosity (η), n—the ratio between the applied shear stress and rate of shear of a liquid at a given temperature.
3.1.2.1 Discussion—
It is sometimes called the coefficient of dynamic viscosity or, simply, viscosity. Thus, dynamic viscosity is a measure of the
resistance to flow or to deformation of a liquid under external shear forces.
3.1.2.2 Discussion—
The term dynamic viscosity can also be used in a different context to denote a frequency-dependent quantity in which shear stress
and shear rate have a sinusoidal time dependence.
3.1.3 kinematic viscosity, n—the ratio of the dynamic viscosity (η) to the density (ρ) of a liquid at a given temperature.
3.1.3.1 Discussion—
For gravity flow under a given hydrostatic head, the pressure head of a liquid is proportional to its density, (ρ). Therefore, the
kinematic viscosity, (ν), is a measure of the resistance to flow of a liquid under gravity.
3.1.4 rate of shear (shear rate), n—in liquid flow, the velocity gradient across the liquid.
3.1.5 shear stress, n—the force per unit area in the direction of the flow.
3.1.5.1 Discussion—
The SI unit for shear stress is the pascal (Pa).
3.2 Definitions of Terms Specific to This Standard:
3.2.1 oscillating piston viscometer, n—a device that measures the travel time of a piston driven electromagnetically into stationary
oscillating motion through a liquid at a controlled force in order to determine the dynamic viscosity of the liquid.
4. Summary of Test Method
4.1 A specimen of sample is placed in the thermally controlled measurement chamber where the piston resides. The piston is
driven into oscillatory motion within the measurement chamber by a controlled magnetic field. Once the sample is at the test
temperature, as determined by the temperature detector, the piston is propelled repeatedly through the liquid (by the magnetic
field). A shear stress (ranging from 5 Pa to 750 Pa) is imposed on the liquid under test due to the piston travel. The dynamic
viscosity is determined by measuring the average travel time of the piston. The kinematic viscosity is derived by additionally
measuring the ratio between the up and down travel times. This information is then applied to a calibration curve using liquids
of known viscosity to calculate the dynamic viscosity. The kinematic viscosity is derived by an externally measured density by
additionally measuring the ratio between the up and down travel times. The precision and bias data for kinematic viscosity (as
published in RR:D02-1755 ) were derived by externally measured density and do not apply to the internal density measurement.
Available from International Organization for Standardization (ISO), 1, ch. de la Voie-Creuse, Case postale 56, CH-1211, Geneva 20, Switzerland, http://www.iso.ch.
Available from http://physics.nist.gov/ccu/Uncertainty/index.html.
Supporting data have been filed at ASTM International Headquarters and may be obtained by requesting Research Report RR:D02-1755. Contact ASTM Customer
Service at [e-mail].
D7483 − 21
FIG. 1 Viscometer with Electronics
5. Significance and Use
5.1 Many petroleum products, as well as non-petroleum materials, are used as lubricants for bearings, gears, compressor cylinders,
hydraulic equipment, etc. Proper operation of this equipment depends upon the viscosity of these liquids.
5.2 Oscillating piston viscometers allow viscosity measurement of a broad range of materials including transparent, translucent
and opaque liquids. The measurement principle and stainless steel construction makes the Oscillating Piston Viscometer resistant
to damage and suitable for portable operations. The measurement itself is automatic and does not require an operator to time the
oscillation of the piston. The electromagnetically driven piston mixes the sample while under test. The instrument requires a sample
volume of less than 5 mL and typical solvent volume of less than 10 mL which minimizes cleanup effort and waste.
6. Apparatus
6,7
6.1 Oscillating Piston Viscometer:
6.1.1 The oscillating piston viscometer (see Fig. 1) comprises a measurement chamber and calibrated piston capable of measuring
the dynamic viscosity within the limits of precision given in Section 16.
6.1.2 Piston—Free moving, magnetically driven body within a Oscillating Piston Viscometer which is used for measuring the
viscosity of liquids. Individual pistons are sized to measure specific viscosity ranges by varying the sensor annulus. See Table 1
for the selection of the piston according to the viscosity range.
6.1.3 Measurement Chamber—Location within Oscillating Piston Viscometer where piston motion (through the liquid under test)
occurs due to an imposed electromagnetic field. See Fig. 2.
6.1.4 Electronics—Capable of controlling the electromagnetic field to propel and detect the travel time of the piston with a
discrimination of 0.01 s or better and uncertainty within 60.07 %. The travel time is calibrated to be between 0.4 s and 60 s, at
a distance of 5 mm.
6.1.5 Temperature Controlled Jacket—Sufficient for maintaining measurement chamber temperature within 60.06 °C.
6.1.6 Temperature Measuring Device—Industrial platinum resistance thermometer (IPRT) or equivalent sensor with a maximum
permissible error of 60.02 °C. It is recommended, that the temperature measuring device be verified with an independent,
calibrated temperature probe at the test temperature.
The Oscillating Piston Viscometer is covered by a patent. Interested parties are invited to submit information regarding the identification of an alternative to this patented
item to the ASTM International headquarters. Your comments will receive careful consideration at a meeting of the responsible technical committee, which you may attend.
The sole sources of supply for the apparatus known to the committee at this time is Cambridge Viscosity Inc., 101 Station Landing, Medford, MA 02155
(www.cambridgeviscosity.com). If you are aware of alternative suppliers, please provide this information to ASTM International Headquarters. Your comments will receive
careful consideration at a meeting of the responsible technical committee, which you may attend.
D7483 − 21
TABLE 1 Viscosity Ranges of Oscillating Viscometer Pistons
Minimum Viscosity (mPa·s ) Maximum Viscosity (mPa·s ) Piston Designation Nominal Piston Diameter (mm) Recommended Sample Volume
(mL)
0.02 2 SP20 7.87 3.2–5
0.25 5 SP50 7.83 3.2–5
0.5 10 SP11 7.81 3.2–5
1 20 SP21 7.76 3.5–5
2.5 50 SP51 7.68 3.5–5
5 100 SP12 7.62 3.5–5
10 200 SP22 7.54 3.5–5
25 500 SP52 7.34 3.5–5
50 1000 SP13 7.21 4.0–5
100 2000 SP23 6.96 4.0–5
250 5000 SP53 6.27 4.0–5
500 10 000 SP14 6.05 4.0–5
1000 20 000 SP24 5.72 4.0–5
FIG. 2 Cross Sectional View of Measurement Chamber
6.2 Temperature Regulation System:
6.2.1 Any liquid bath or thermoelectric means for regulating the jacket temperature.
6.2.2 The temperature control must be such that the temperature of the measurement chamber is held within 60.06 °C of the
desired measurement temperature.
6.3 Sample Introduction Mechanism—A syringe, micropipette, or flow-through adapter for introducing between 3.2 mL and 5 mL,
inclusive by pressure, into the measurement chamber.
7. Reagents and Materials
7.1 Certified viscosity reference standards shall be certified by a laboratory that has been shown to meet the r
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