ASTM D4308-95(2000)
(Test Method)Standard Test Method for Electrical Conductivity of Liquid Hydrocarbons by Precision Meter
Standard Test Method for Electrical Conductivity of Liquid Hydrocarbons by Precision Meter
SCOPE
1.1 This test method applies to the determination of the "rest" electrical conductivity of aviation fuels and other similar low-conductivity hydrocarbon liquids in the range from 0.1 to 2000 pS/m (see 3.2). This test method can be used in the laboratory or in the field.
1.2 The values stated in SI units are to be regarded as the 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. For specific hazard statements, see 7.1.1 and 7.2.
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NOTICE: This standard has either been superseded and replaced by a new version or discontinued.
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Designation: D 4308 – 95 (Reapproved 2000) An American National Standard
Standard Test Method for
Electrical Conductivity of Liquid Hydrocarbons by Precision
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Meter
This standard is issued under the fixed designation D 4308; 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 (e) indicates an editorial change since the last revision or reapproval.
This standard has been approved for use by agencies of the Department of Defense.
1. Scope current measurement after a d-c voltage is impressed between
electrodes.
1.1 This test method applies to the determination of the
“rest” electrical conductivity of aviation fuels and other similar
4. Summary of Test Method
low-conductivity hydrocarbon liquids in the range from 0.1 to
4.1 A sample of liquid hydrocarbon is introduced into a
2000 pS/m (see 3.2). This test method can be used in the
clean conductivity cell which is connected in series to a battery
laboratory or in the field.
voltage source and a sensitive dc ammeter. The conductivity,
1.2 The values stated in SI units are to be regarded as the
automatically calculated from the observed peak current read-
standard.
ing dc voltage and cell constant using Ohm’s law, appears as a
1.3 This standard does not purport to address all of the
digital value in either a manual or automatic mode of meter
safety concerns, if any, associated with its use. It is the
operation.
responsibility of the user of this standard to establish appro-
priate safety and health practices and determine the applica-
5. Significance and Use
bility of regulatory limitations prior to use. For specific hazard
5.1 The generation and dissipation of electrostatic charge in
statements, see Notes 2-4.
fuel due to handling depend largely on the ionic species present
2. Referenced Documents which may be characterized by the rest or equilibrium electri-
cal conductivity. The time for static charge to dissipate is
2.1 ASTM Standards:
inversely related to conductivity. This test method can supple-
D 150 Test Methods for A-C Loss Characteristics and
ment Test Method D 2624 which is limited to fuels containing
Permittivity (Dielectric Constant) of Solid Electrical Insu-
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static dissipator additive.
lating Materials
D 2624 Test Methods for Electrical Conductivity of Avia-
NOTE 1—For low-conductivity fluids below 1 pS/m in conductivity, an
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tion and Distillate Fuels a-c measurement technique is preferable to a d-c test method for sensing
the electrical conductivity of bulk fluid. This d-c test method can be used
D 4306 Practice for Aviation Fuel Sample Containers for
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at conductivities from 0.1 to 1 pS/m if precautions are observed in cell
Tests Affected by Trace Contamination
cleaning and sample handling. A waiting period of 15 min is required after
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E 1 Specification for ASTM Thermometers
filling the cell before measuring d-c conductivities below 1 pS/m. A
single-laboratory program was conducted comparing this test method with
3. Terminology
a-c Test Method D 150. The results are on file at ASTM Headquarters.
3.1 picosiemens per metre—the unit of electrical conductiv-
Request RR: D02-1241.
ity is also called a conductivity unit (CU). A siemen is the SI
6. Apparatus
definition of reciprocal ohm sometimes called mho.
6.1 Conductivity Apparatus—Components of the dc con-
212 21 21
1 pS/m 5 1 3 10 V m 5 1cu 5 1 picomho/m (1)
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ductivity apparatus are shown in Fig. 1.
3.2 rest conductivity—the reciprocal of the resistance of
6.1.1 The conductivity cell shown in Fig. 1 consists of an
uncharged fuel in the absence of ionic depletion or polariza-
inner electrode and an outer electrode separated by an insula-
tion. It is the electrical conductivity at the initial instant of
tor. The outer electrode and cap provide a ground path and
electrostatic (Faraday) shield.
6.1.2 The electrometer shown in Fig. 1 contains a battery
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This test method is under the jurisdiction of ASTM Committee D-2 on
which supplies a voltage to the cell and a bridge circuit which
Petroleum Products and Lubricants and is the direct responsibility of Subcommittee
senses the flow of current and converts the output signal
D02.J on Aviation Fuels.
Current edition approved Feb. 15, 1995. Published April 1995. Originally
published as D 4308 – 83. Last previous edition D 4308 – 89.
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Annual Book of ASTM Standards, Vol 10.01. The KSLA Cell and Precision Conductivity Meter System, Emcee Model
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Annual Book of ASTM Standards, Vol 05.02. #1154 are available from Emcee Electronics, Inc., 520 Cypress Ave., Venice, FL
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Annual Book of ASTM Standards, Vol 14.03. 34292.
Copyright © ASTM, 100 Barr Harbor Drive, West Conshohocken, PA 19428-2959, United States.
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