ASTM D4984-20

Standard Test Method for Carbon Dioxide in Natural Gas Using Length-of-Stain Detector Tubes

SIGNIFICANCE AND USE
5.1 The measurement of carbon dioxide in natural gas is important, because of gas quality specifications, the corrosive nature of carbon dioxide on pipeline materials, and the affects of carbon dioxide on utilization equipment.  
5.2 This test method provides inexpensive field screening of carbon dioxide. The system design is such that it may be used by nontechnical personnel with a minimum of proper training.
SCOPE
1.1 This test method covers a rapid and simple field determination of carbon dioxide in natural gas pipelines. Available detector tubes provide a total measuring range of 100 ppm (parts per million) up to 60 % by volume, although the majority of applications will be on the lower end of this range (that is, under 5 %). At least one manufacturer provides a special kit for measurements from 10 to 100 % CO2, but the normal 100 cc hand pump is not used. See Note 1.  
Note 1: High-range carbon dioxide detector tubes will have measuring ranges in percent (%) CO2, and low-range tubes will be in parts per million (ppm). To convert percent to ppm, multiply by 10 000 (1 % = 10 000 ppm).  
1.2 Units—The values stated in SI units are regarded as standard. The inch-pound units in parentheses are for information only.  
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, health, and environmental practices and determine the applicability of regulatory limitations prior to use.  
1.4 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: 14-Dec-2020
• ICS: 75.160.30 - Gaseous fuels
• Technical Committee: D03 - Gaseous Fuels

Relations

• Refers: ASTM D4150-19 - Standard Terminology Relating to Gaseous Fuels
• Effective Date: 15-Dec-2019
• Refers: ASTM D4150-08(2016) - Standard Terminology Relating to Gaseous Fuels
• Effective Date: 01-Jul-2016
• Refers: ASTM D4150-08 - Standard Terminology Relating to Gaseous Fuels
• Effective Date: 01-Dec-2008
• Refers: ASTM D4150-03 - Standard Terminology Relating to Gaseous Fuels
• Effective Date: 10-Aug-2003
• Refers: ASTM D4150-00 - Standard Terminology Relating to Gaseous Fuels
• Effective Date: 10-Jun-2000

Overview

ASTM D4984-20 is the standard test method developed by ASTM International for the rapid and simple field determination of carbon dioxide in natural gas pipelines using length-of-stain detector tubes. The method is specifically designed to offer affordable and straightforward screening for carbon dioxide concentrations, enabling monitoring for compliance with gas quality specifications, mitigating pipeline corrosion risk, and reducing impacts on gas utilization equipment. The test can be performed by nontechnical personnel with minimal training, making it suitable for field conditions where quick results are crucial. Carbon dioxide measurements made with this method support both operational safety and regulatory compliance in natural gas supply chains.

Key Topics

• Field Measurement: The standard details procedures for quickly measuring carbon dioxide in natural gas streams using portable detector tube systems, which are both easy to use and cost-effective.
• Detection Range: Commercially available detector tubes can measure carbon dioxide concentrations from as low as 100 ppm (parts per million) up to 60% by volume, covering a wide range of applications. Most pipeline monitoring typically focuses on detecting levels under 5%.
• Detector Tube System: The method utilizes a calibrated hand-operated pump and colorimetric detector tubes containing chemicals specific to carbon dioxide. The length of the color change in the tube is proportional to the carbon dioxide concentration.
• Sampling Technique: Procedures are outlined for proper gas sample collection to ensure representative and reliable results, including guidelines for setting up sample probes, using sampling chambers, or employing collection bags.
• Accuracy and Limitations: While accuracy is generally ±25%, the test acknowledges possible interferences from other gases and emphasizes the importance of following manufacturer-specific instructions and proper sampling techniques.

Applications

This standard is widely used in the natural gas industry for several practical purposes:

• Pipeline Quality Monitoring: Regular screening for carbon dioxide is critical in ensuring that natural gas meets contractual and regulatory quality standards.
• Corrosion Prevention: Elevated carbon dioxide levels contribute to pipeline corrosion, posing a threat to infrastructure integrity and safety. Early detection allows for timely mitigation.
• Equipment Protection: Excess carbon dioxide can impair the performance or lifespan of downstream gas utilization equipment such as turbines, compressors, and burners. Routine testing minimizes operational risks.
• Field Operations: The test method is ideally suited for field operators, engineers, and inspectors who require rapid, on-site results without extensive laboratory support.
• Regulatory Compliance: Many jurisdictions require periodic monitoring of gas composition. This method offers a practical tool to demonstrate compliance with environmental and safety standards.

Related Standards

ASTM D4984-20 references and aligns with several other industry standards, including:

• ASTM D4150: Terminology Relating to Gaseous Fuels - provides definitions for terms commonly used in the analysis of gaseous fuels.
• GPA 2337: Gas Processors Association’s standard for testing hydrogen sulfide and carbon dioxide in natural gas using detector tubes.
• International Guidelines: Developed in accordance with WTO Technical Barriers to Trade principles for harmonized test methods in trade.

Conclusion

ASTM D4984-20 offers a pragmatic and efficient approach to carbon dioxide determination in natural gas. By facilitating quick, reliable, and affordable field analysis, it helps ensure gas quality, pipeline longevity, and system safety. The method’s simplicity, broad measurement range, and suitability for field use make it an essential standard for natural gas pipeline operators and quality assurance personnel. For more detailed procedures, users should always consult the latest official ASTM publication.

Keywords: ASTM D4984-20, carbon dioxide in natural gas, detector tubes, field test method, pipeline gas quality, gas sampling, corrosion prevention, natural gas standards, portable gas detection, CO2 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: D4984 − 20
Standard Test Method for
Carbon Dioxide in Natural Gas Using Length-of-Stain
Detector Tubes
This standard is issued under the fixed designation D4984; 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 2.2 GPA Standard:
2337 Test for Hydrogen Sulfide and Carbon Dioxide in
1.1 This test method covers a rapid and simple field deter-
Natural Gas Using Length-of-Stain Tubes
mination of carbon dioxide in natural gas pipelines. Available
detector tubes provide a total measuring range of 100 ppm
3. Terminology
(parts per million) up to 60 % by volume, although the majority
3.1 Definitions—For definitions of general terms used in
of applications will be on the lower end of this range (that is,
D03 Gaseous Fuels standards, refer to Terminology D4150.
under 5 %). At least one manufacturer provides a special kit for
measurements from 10 to 100 % CO , but the normal 100 cc
3.2 Definitions of Terms Specific to This Standard:
hand pump is not used. See Note 1.
3.2.1 detector tube pump, n—a hand-operated pump of a
piston or bellows type.
NOTE 1—High-range carbon dioxide detector tubes will have measuring
3.2.1.1 Discussion—It must be capable of drawing 100 mL
ranges in percent (%) CO , and low-range tubes will be in parts per
million (ppm). To convert percent to ppm, multiply by 10 000 per stroke of sample through the detector tube with a volume
(1 % = 10 000 ppm).
tolerance of 65 mL. It must be specifically designed for use
with detector tubes.
1.2 Units—The values stated in SI units are regarded as
3.2.1.2 Discussion—A detector tube and pump together
standard. The inch-pound units in parentheses are for informa-
form a unit and must be used as such. Each manufacturer
tion only.
calibrates detector tubes to match the flow characteristics of
1.3 This standard does not purport to address all of the
their specific pump. Crossing brands of pumps and tubes is not
safety concerns, if any, associated with its use. It is the
permitted, as considerable loss of system accuracy is likely to
responsibility of the user of this standard to establish appro-
occur.
priate safety, health, and environmental practices and deter-
3.2.2 gas sampling chamber, n—any container that provides
mine the applicability of regulatory limitations prior to use.
for access of the detector tube into a uniform flow of sample
1.4 This international standard was developed in accor-
gas at atmospheric pressure and isolates the sample from the
dance with internationally recognized principles on standard-
surrounding atmosphere.
ization established in the Decision on Principles for the
3.2.2.1 Discussion—A stainless steel needle valve (or pres-
Development of International Standards, Guides and Recom-
sure regulator) is placed between the source valve and the
mendations issued by the World Trade Organization Technical
sampling chamber for the purpose of throttling the sample
Barriers to Trade (TBT) Committee.
flow. Flow rate should approximate 1 to 2 volume changes per
minute or, at minimum, provide exit gas flow throughout the
2. Referenced Documents
detector tube-sampling period.
2.1 ASTM Standards:
3.2.2.2 Discussion—A suitable sampling chamber may be
D4150 Terminology Relating to Gaseous Fuels
devised from a polyethylene wash bottle of nominal 500 mL
(16 oz) or 1 L (32 oz) size. The wash bottle’s internal delivery
tube provides for delivery of sample gas to the bottom of the
bottle. A 14.7 mm ( ⁄2 in.) hole cut in the bottle’s cap provides
This test method is under the jurisdiction of ASTM Committee D03 on Gaseous
Fuels and is the direct responsibility of Subcommittee D03.06.03 on Analysis by
access for the detector tube and vent for the purge gas (see Fig.
Spectroscopy.
1). (An alternate flow-through sampler may be fashioned using
Current edition approved Dec. 15, 2020. Published January 2021. Originally
approved in 1989. Last previous edition approved in 2015 as D4984 – 06(2015).
DOI: 10.1520/D4984-20.
2 3
For referenced ASTM standards, visit the ASTM website, www.astm.org, or Available from Gas Processors Association (GPA), 6060 American Plaza, Suite
contact ASTM Customer Service at [e-mail]. For Annual Book of ASTM 700, Tulsa, OK 74135, http://www.gpaglobal.org.
Standards volume information, refer to the standard’s Document Summary page on Direct Reading Colorimetric Indicator Tubes Manual, Second Edition, Ameri-
the ASTM website. can Industrial Hygiene Association, Publication No. 172-SI-93, 1993.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
D4984 − 20
proportional to the amount of carbon dioxide present in the
sample. A hand-operated piston or bellows-type pump is used
to draw a measured volume of sample through the tube at a
controlled rate of flow. The length of stain produced is
converted to parts per million (ppm) or percent (%) carbon
dioxide by comparison to a calibration scale supplied by the
manufacturer for each box of detection tubes. The system is
direct reading, easily portable, and completely suited to making
rapid spot checks for carbon dioxide under field conditions.
(See Note 1.)
5. Significance and Use
5.1 The measurement of carbon dioxide in natural gas is
important, because of gas quality specifications, the corrosive
nature of carbon dioxide on pipeline materials, and the affects
of carbon dioxide on utilization equipment.
5.2 This test method provides inexpensive field screening of
carbon dioxide. The system design is such that it may be used
by nontechnical personnel with a minimum of proper training.
6. Interferences
6.1 Detector tubes are usually subject to interferences from
gases and vapors other than the target substance. Such inter-
ferences may vary among brands as a result of the use of
FIG. 1 Apparatus Schematic
different detection methods. Some detector tubes will have a
“precleanse” layer designed to remove interferences up to
a 1 gal (3.8 L) “zipper”-type food storage bag. The flexible line
some maximum interferent level. Consult manufacturer’s in-
enters one corner of the bag’s open end and extends to the
structions for specific interference information.
bottom of the bag. The opposite corner of the bag’s top is
sealed shut. The basic procedure for the sampler in Fig. 1
7. Procedure
applies.)
7.1 Select a sampling point that provides access to a
3.2.2.3 Discussion—An alternate sampling container is a
representative sample of the gas being tested (source valve on
collection bag made of a material suitable for the collection of
the main line). The sample point should be on top of the
natural gas (for example, polyester film). The sampling bag
pipeline and equipped with a stainless steel sample probe
should have a minimum capacity of 2 L.
extending into the middle third of the pipeline. Open the source
3.2.3 length-of-stain detector tube, n—a sealed glass tube
valve momentarily to clear the valve and connecting nipple of
with break-off tips sized to fit the tube holder of the pump.
foreign materials.
3.2.3.1 Discussion—The reagent layer inside the tube, typi-
7.2 Install needle valve (or pressure regulator) at the source
cally a silica gel substance coated with the active chemicals,
valve outlet. Connect sampling chamber using the shortest
must be specific for carbon dioxide and produce a distinct color
length of flexible tubing possible (see Fig. 1). Most flexible
change when exposed to a sample of gas containing carbon
tubing material will be suitable for carbon dioxide sampling;
dioxide. Any substances known to interfere must be listed in
however, if the sample
...

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: D4984 − 06 (Reapproved 2015) D4984 − 20
Standard Test Method for
Carbon Dioxide in Natural Gas Using Length-of-Stain
Detector Tubes
This standard is issued under the fixed designation D4984; 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 a rapid and simple field determination of carbon dioxide in natural gas pipelines. Available detector
tubes provide a total measuring range of 100 ppm (parts per million) up to 60 % by volume, although the majority of applications
will be on the lower end of this range (that is, under 5 %). At least one manufacturer provides a special kit for measurements from
10 to 100 % CO , but the normal 100-cc100 cc hand pump is not used. See Note 1.
NOTE 1—High-range carbon dioxide detector tubes will have measuring ranges in percent (%) CO , and low-range tubes will be in parts per million (ppm).
To convert percent to ppm, multiply by 10 000 (1 % = 10 000 ppm).
1.2 Units—The values stated in SI units are regarded as standard. The inch-pound units in parentheses are for information only.
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 safety, health, and healthenvironmental practices and determine the
applicability of regulatory limitations prior to use.
1.4 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:
D4150 Terminology Relating to Gaseous Fuels
2.2 Gas Processors Association GPA Standard:
2337 Test for Hydrogen Sulfide and Carbon Dioxide in Natural Gas Using Length-of-Stain Tubes
3. Terminology
3.1 Definitions—For definitions of general terms used in D03 Gaseous Fuels standards, refer to Terminology D4150.
3.2 Definitions of Terms Specific to This Standard:
This test method is issued under the jurisdiction of ASTM Committee D03 on Gaseous Fuels and is the direct responsibility of Subcommittee D03.07 on Analysis of
Chemical Composition of Gaseous Fuels.
Current edition approved Nov. 1, 2015Dec. 15, 2020. Published December 2015January 2021. Originally approved in 1989. Last previous edition approved in 20112015
as D4984D4984 – 06–06 (2011). (2015). DOI: 10.1520/D4984-06R15.10.1520/D4984-20.
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.
Available from Gas Processors Association, 6526 East 60th St., Tulsa, OK 74145.Association (GPA), 6060 American Plaza, Suite 700, Tulsa, OK 74135,
http://www.gpaglobal.org.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
D4984 − 20
3.2.1 detector tube pump—pump, n—a hand-operated pump of a piston or bellows type. It must be capable of drawing 100 mL
per stroke of sample through the detector tube with a volume tolerance of 65 mL. It must be specifically designed for use with
detector tubes.
3.2.1.1 Discussion—
It must be capable of drawing 100 mL per stroke of sample through the detector tube with a volume tolerance of 65 mL. It must
be specifically designed for use with detector tubes.
3.2.1.2 Discussion—
A detector tube and pump together form a unit and must be used as such. Each manufacturer calibrates detector tubes to match
the flow characteristics of their specific pump. Crossing brands of pumps and tubes is not permitted, as considerable loss of system
accuracy is likely to occur.
3.1.1.1 Discussion—A detector tube and pump together form a unit and must be used as such. Each manufacturer calibrates
detector tubes to match the flow characteristics of their specific pump. Crossing brands of pumps and tubes is not permitted, as
considerable loss of system accuracy is likely to occur.
3.2.2 gas sampling chamber—chamber, n—any container that provides for access of the detector tube into a uniform flow of
sample gas at atmospheric pressure and isolates the sample from the surrounding atmosphere. A stainless steel needle valve (or
pressure regulator) is placed between the source valve and the sampling chamber for the purpose of throttling the sample flow.
Flow rate should approximate 1 to 2 volume changes per minute or, at minimum, provide exit gas flow throughout the detector
tube-sampling period.
3.2.2.1 Discussion—
A stainless steel needle valve (or pressure regulator) is placed between the source valve and the sampling chamber for the purpose
of throttling the sample flow. Flow rate should approximate 1 to 2 volume changes per minute or, at minimum, provide exit gas
flow throughout the detector tube-sampling period.
3.2.2.2 Discussion—
A suitable sampling chamber may be devised from a polyethylene wash bottle of nominal 500-mL (16-oz) or 1-L (32-oz)500 mL
(16 oz) or 1 L (32 oz) size. The wash bottle’s internal delivery tube provides for delivery of sample gas to the bottom of the bottle.
A 14.7-mm14.7 mm ( ⁄2-in.) in.) hole cut in the bottle’s cap provides access for the detector tube and vent for the purge gas (see
Fig. 1). (An alternate flow-through sampler may be fashioned using a 1-gal (3.8-L)1 gal (3.8 L) “zipper”-type food storage bag.
The flexible line enters one corner of the bag’s open end and extends to the bottom of the bag. The opposite corner of the bag’s
top is sealed shut. The basic procedure for the sampler in Fig. 1 applies.)
3.2.2.3 Discussion—
An alternate sampling container is a collection bag made of a material suitable for the collection of natural gas (for example,
polyester film). The sampling bag should have a minimum capacity of 2 L.
3.2.3 length-of-stain detector tube—tube, n—a sealed glass tube with break-off tips sized to fit the tube holder of the pump. The
reagent layer inside the tube, typically a silica gel substance coated with the active chemicals, must be specific for carbon dioxide
and produce a distinct color change when exposed to a sample of gas containing carbon dioxide. Any substances known to interfere
must be listed in the instructions accompanying the tubes. A calibration scale should be marked directly on the tube; however, other
markings that provide for easy interpretation of carbon dioxide content from a separate calibration scale supplied with the tubes
shall be acceptable. The calibration scale shall correlate carbon dioxide concentration to the length of the color stain. Shelf life of
the detector tubes must be a minimum of two years from the date of manufacture when stored according to manufacturers’
recommendations.
3.2.3.1 Discussion—
The reagent layer inside the tube, typically a silica gel substance coated with the active chemicals, must be specific for carbon
dioxide and produce a distinct color change when exposed to a sample of gas containing carbon dioxide. Any substances known
to interfere must be listed in the instructions accompanying the tubes. A calibration scale should be marked directly on the tube;
however, other markings that provide for easy interpretation of carbon dioxide content from a separate calibration scale supplied
with the tubes shall be acceptable. The calibration scale shall correlate carbon dioxide concentration to the length of the color stain.
Shelf life of the detector tubes must be a minimum of two years from the date of manufacture when stored according to
manufacturers’ recommendations.
4. Summary of Test Method
4.1 The sample is passed through a detector tube filled with a specially prepared chemical. Any carbon dioxide present in the
\Direct Reading Colorimetric Indicator Tubes Manual, First ed.,Second Edition, American Industrial Hygiene Association, Akron, OH 44311.Publication No. 172-SI-93,
1993.
D4984 − 20
FIG. 1 Apparatus Schematic
sample reacts with the chemical to produce a color change or stain. The length of the stain produced in the detector tube, when
exposed to a measured volume of sample, is directly proportional to the amount of carbon dioxide present in the sample. A
hand-operated piston or bellows-type pump is used to draw a measured volume of sample through the tube at a controlled rate of
...