ISO/FDIS 24895-1

ISO/TC 193/SC 1
Secretariat: NEN
Date: 2026-05-2109-18
Analysis of natural gas — Determination of particulate matter — —
Part 1:
Determination of particleparticles content by gravimetric method
Analyse du gaz naturel — Détermination des particules en suspension —
Partie 1: Détermination de la teneur en particules par méthode gravimétrique
FDIS stage
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ISO/DISFDIS 24895-1:20252026(en)
Contents
Foreword . iv
Introduction . v
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
4 Test principle . 1
5 Apparatus and materials . 1
6 Sampling and determination . 6
6.1 Sampling location and installation of sampling probe . 6
6.2 Constant mass of filter membrane and filter cartridge . 6
6.3 Sampling procedure . 6
6.4 Determination of final mass . 8
6.5 Repeated measurements . 8
7 Calculation . 8
7.1 Calculation of gas sample corrected volume. 8
7.2 Calculation of particulate matter content . 8
8 Uncertainty evaluation . 8
8.1 Principle . 8
8.2 Uncertainty of m . 9
8.3 Uncertainty of m . 9
8.4 Uncertainty of m . 9
8.5 Uncertainty of V . 10
8.6 Uncertainty of P . 10
8.7 Uncertainty of T . 10
8.8 Uncertainty of V . 10
n
8.9 Uncertainty of result . 11
8.10 Relative expanded uncertainty of result . 11
8.11 Expanded uncertainty of result . 11
9 Test report . 11
Annex A (informative) Example of the determination of particles content in natural gas . 12

iii
Foreword
ISO (the International Organization for Standardization) is a worldwide federation of national standards
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This document was prepared by Technical Committee ISO/TC 193, Natural gas, Subcommittee SC 1, Analysis
of natural gas.
A list of all parts in the ISO 24895 series can be found on the ISO website.
Any feedback or questions on this document should be directed to the user’s national standards body. A
complete listing of these bodies can be found at www.iso.org/members.html.

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ISO/DISFDIS 24895-1:20252026(en)
Introduction
Particulate matter is an important factor in natural gas quality. Its presence not only affects the safety of
natural gas pipeline transmission but is also detrimental to the normal and smooth operation of end-use
equipment. In serious cases, it can also lead to the failure and damage of end-use equipment (e.g. a
compressor). There is great demand for a standard method of determination of particulate matter in natural
gas and its substitutes, especially coalbed methane. There are often requirements for particulate matter in
natural gas in international trade.
v
DRAFT International Standard ISO/DIS 24895-1:2025(en)

Analysis of natural gas - — Determination of particulate matter - —
Part 1:
Determination of particleparticles content by gravimetric method
1 Scope
This document specifies the test principle, apparatus, materials, sampling, determination, calculation and
reporting requirements for the determination of particulate matter content in natural gas by a gravimetric
method.
Unless otherwise specified, the volume standard reference conditions used in this document are 101,325 kPa
and 273,15 K.
2 Normative references
The following documents are referred to in the text in such a way that some or all of their content constitutes
requirements of this document. For dated references, only the edition cited applies. For undated references,
the latest edition of the referenced document (including any amendments) applies.
ISO 10715, Natural gas — Gas sampling
3 Terms and definitions
No terms and definitions are listed in this document.
ISO and IEC maintain terminology databases for use in standardization at the following addresses:
— — ISO Online browsing platform: available at https://www.iso.org/obp
— — IEC Electropedia: available at https://www.electropedia.org/
4 Test principle
A certain volume of natural gas passes through a pretreated and weighed filter membrane or filter cartridge,
on which the particulate matter is captured. After drying and weighing, the particulate matter content is
calculated by the mass gain of the filter membrane or filter cartridge, attributed to particulate matter, for the
natural gas volume passing through.
5 Apparatus and materials
5.1 5.1 Sampling probe, thewhich can be fixed sampling probe or retractable sampling probe
isas shown in Figure 1Figure 1, which is, made of stainless steel with an external diameter of 6 mm to
10 mm (internal diameter of 4 mm to 7 mm). Natural gas enters from the front end of the elbow of the
sampling probe.
5.2
5.3
5.4
5.5
5.6 Unit：mm
5.7
Key
“→” direction of gas flow
“
D” external diameter (6 mm to 10 mm)
“d” internal diameter (4 mm to 7 mm)
Figure 1 — Sampling probe diagram
5.85.2 5.2 Sampling tube:, made of stainless steel tube, with an external diameter of 6 mm to 10 mm
(internal diameter of 4 mm to 7 mm). The sampling tube from the probe to the trap shall be as short as
possible. It shall not exceed 3 m.
5.95.3 5.3 Particulate matter filter, consisting of the following.
a) 5.3.1 Particulate matter filter, which shall be sulfur-resistant (components of natural gas shall not
cause mass change of filter), with a working pressure 12 MPa, and used to capture particulate matter
under pipeline pressure.
b) 5.3.2 Membrane type filter, made of glass fibre and other materials. The maximum pore diameter is
not more than 0,3 μm. See Figure 2Figure 2.
c) 5.3.3 Cartridge type filter, the. The filter cartridge is sintered from metal, such as titanium alloy, and
the maximum pore diameter is not more than 0,3 μm. See Figure 3Figure 3.
NOTE There are filter products to capture particleparticles with a diameter of not more than 0,1 μm, and using.
Using these filters can increase the capture efficiency.
5.105.4 5.4 Gas meter with maximum permissible error (MPE) of 1,5 % or better.
5.115.5 5.5 Thermometer with a range from 0 °C to 50 °C and a resolution of 0,1 °C.
5.125.6 5.6 Atmospheric pressure gauge with a range from 80 kPa to 106 kPa and a
resolution of 0,1 kPa.
5.135.7 5.7 Glass desiccator:, packed with colour-changing silica gel.
5.145.8 5.8 Analytical balance, with a resolution of 0,1 mg.
5.155.9 5.9 Weighing bottle: ;before use, the weighing bottle should be cleaned, dried
and cooled in a desiccator.
ISO/DISFDIS 24895-1:20252026(en)
5.165.10 5.10 Gloves:, i.e. cotton gloves.

Key
1 upper body of filter
2 connecting hole
3 intake-tube
4 stainless steel net
5 filter membrane
6 sealing ring
7 lower body of filter
8 exhaust tube
→ direction of gas flow
Figure 2 — Membrane type filter body diagram
ISO/DISFDIS 24895-1:20252026(en)

Key
1 intake tube
2 upper body of filter
3 sealing gasket
4 bolt
5 cartridge
6 lower body of filter
7 exhaust tube
→ direction of gas flow
Figure 3 — Cartridge type filter body diagram
6 Sampling and determination
6.1 Sampling location and installation of sampling probe
The sampling location shall be in a straight pipe section of the transmission pipeline. A vertical straight pipe
section shall be selected. The minimum length of straight pipe both upstream and downstream of the sampling
location shall not be less than three times the pipe internal diameter.
The sampling probe shall be inserted at one-third to one-sixth of the inner diameter of the pipe, facing the
direction of the gas flow.
6.2 Constant weightmass of filter membrane and filter cartridge
6.2.1 Initial mass of filter membrane
Before sampling, gloves shall be put on and a filter membrane shall be placed in the weighing bottle (5.9(5.9),),
which shall then dry itbe dried with the lid (leave the lid off) in a glass desiccator (5.7(5.7).). After 20 min of
drying, close the lid of the weighing bottle and weigh the bottle and membrane using the analytical balance
(5.8(5.8).). Dry (with lid removed) for another 20 min and weigh again. If the difference of the two
weightsmasses is less than 0,2 mg, it is considered to have reached a constant weightmass. Record the pre-
sampling constant weightmass. Otherwise, continue drying and weighing until constant weightmass is
achieved.
6.2.2 Initial mass of filter cartridge
Before sampling, gloves shall be put on and a filter cartridge shall be placed in the glass desiccator (5.7(5.7))
to dry. After 20 min of drying, weigh it using the analytical balance (5.8(5.8).). Dry for another 20 min and
weigh again. If the difference of the two weightsmasses is less than 0,2 mg, it is considered to have reached a
constant weightmass. Record the pre-sampling constant weightmass. Otherwise, continue drying and
weighing until constant weightmass is achieved.
6.3 Sampling procedure
6.3.1 Summary
Sampling shall be carried out in accordance with ISO 10715.
The layout of the sampling apparatus for determining particulate matter content is shown in Figure 4Figure 4.
Connect the devices using the sampling tube (5.2
...