🌿 Determination of the mass concentration of methane in waste gases from stationary sources by a manual method — sampling with a probe (heated to 150 °C if necessary) through a filter and a cooler into a bag, glass ampoule or canister (5–30 l), including by the “lung principle”, flow up to 1 l/min, analysis by gas chromatography with flame ionisation detection (GC-FID); independent method (SRM according to EN 14181) validated up to 1500 mg/m3, PN-EN ISO 25139

Environment PN-EN ISO 25139

Overview

WHAT THE STANDARD COVERS. The scope on the PKN catalogue card of PN-EN ISO 25139:2011 (English version), in full (our translation): “This International Standard specifies a manual method for the determination of the methane concentration in emissions from stationary sources. This International Standard specifies an independent measurement method, validated in the range of mass concentrations up to 1 500 mg/m3. NOTE 1 An independent measurement method is used for purposes such as calibration or validation of permanently installed measuring systems. NOTE 2 An »independent measurement method« is called a »standard reference method (SRM)« in EN 14181”. We read the text of the standard in the iTeh sample of ISO 25139:2011 (French version): from the contents through the foreword, introduction and Clauses 1–5 up to and including 6.1 (sampling system). Outside the sample remain 6.2 (analytical system), Clauses 7 (sampling, determination, interferences), 8 (calculations), 9 (quality assurance and control, checking of the measuring system), 10 (performance characteristics), 11 (test report) and Annexes A (operating gases), B (quality control procedures) and C (typical performance characteristics). We also checked the sample of SIST EN ISO 25139:2011 (text of EN ISO 25139:2011) — title pages.

ACCORDING TO THE TEXT OF ISO 25139:2011 (Clauses 1–5, 6.1). The standard was prepared by ISO/TC 146 “Air quality”, subcommittee SC 1 “Stationary source emissions”. Introduction: methane is an important greenhouse gas; natural sources and human activity — among others cattle breeding, rice cultivation, extraction and transport of natural gas, landfills, composting plants, biogas and natural gas, biomass burning. Scope (1): a manual method for determining the methane concentration in emissions from stationary sources; an independent method validated up to mass concentrations of 1500 mg/m3 (note 1: an independent method is used e.g. for calibrating or validating permanently installed systems; note 2: in EN 14181 it is called the standard reference method, SRM). Normative references (2): ISO 9169 (performance characteristics of automatic measuring systems), EN 15267-3 (certification of automated measuring systems for emissions). Definitions (3): reference gas (of known, traceable and stable composition — here for calibrating the chromatograph), interferent, mass concentration (mass per volume, usually mg/m3), uncertainty and standard uncertainty. Symbols (4): among others the molar mass of methane 16 g/mol, of water 18 g/mol, the molar volume under standard conditions 22.4 l/mol; mass concentration of methane under standard conditions, in dry gas and at reference oxygen conditions. Principle (5): a gas sample is taken from the duct with a sampling system into a gas bag or a metal can (canister), part of the sample is introduced into a gas chromatograph and, after separation on a packed or capillary column, methane is determined with a flame ionisation detector. Sampling system (6.1): probe, particle filter, gas cooler, flow meter, pump, if necessary a vacuum pump, gas container (bag, glass ampoule or canister) or the sampling loop of the chromatograph; techniques — bag with the pump upstream, evacuated glass ampoule or stainless steel canister with the pump upstream, “lung principle” with the bag in an evacuated container, line led directly to the sampling loop; the line as short as possible, sloping down towards the cooler, without condensation at any point; probe of stainless steel or glass, with a valve for introducing check gases, heated to 150 °C if necessary; filter of ceramic or quartz fibre, heated to 150 °C; line of stainless steel or PTFE, heated to 150 °C; cooler or permeation dryer for a flow up to 1 l/min; gas-tight pump with flow control up to 1 l/min; vacuum pump down to a residual pressure of 10–20 hPa; connections of inert materials (PTFE, fluororubber); gas-tight container with a volume of 5–30 l.

STATUS (card as of 03.10.2026). The PKN card of PN-EN ISO 25139:2011 (English version, published 30-09-2011, 21 pages, price group L) has no “Withdrawn” header: Health, Environment and Medicine Sector, KT 280 Air Quality, ICS 13.040.40, “Introduces: EN ISO 25139:2011 [IDT], ISO 25139:2011 [IDT]”. There is no Polish language version in the PKN search (term “PN-EN ISO 25139”, 03.10.2026). In the iTeh catalogue (read on 03.10.2026) ISO 25139:2011 has the status “Published” and stage 90.93 “International Standard confirmed” (completed on 29.08.2026).

HOW MANY LABORATORIES AND IN WHAT FORM (copy of the accreditation scope database, load up to 17.09.2026, read on 03.10.2026). The number 25139 appears in 9 records at 4 laboratories: AB 409, AB 550, AB 782, AB 974. In the current PCA documents (read on 03.10.2026, issues from 10.10.2025 to 22.09.2026) the number appears in 5 rows of the same 4 laboratories (AB 409 — 2, the others 1 each); there are more records because the copy splits an item “sampling + emission by calculation” into two records. The form is “PN-EN ISO 25139:2011” everywhere; AB 782 marks the item with the symbol “←”, which in its document denotes tests for which the laboratory gives opinions and interpretations in its reports. The “Laboratories” tab (“PN-EN ISO 25139”) shows the same 4 laboratories — checked with the tab query on the production server labcoda.pl on 03.10.2026.

WHAT THE LABORATORIES TEST (items in PCA). Waste gases. Only AB 409 has the methane concentration by GC-FID in its scope: (0.0012–0.3) %. The remaining items are “Sampling for the determination of methane concentration” with “Methane emission (by calculation)”: AB 409, AB 550, AB 782 and AB 974. AB 550 measures methane separately by a continuous method with a flame ionisation detector (HFID) according to PN-EN ISO 25140:2011, (0.3–11) mg/m3. Conversion of the upper limit of AB 409 with the constants from Clause 4 of the standard (16 g/mol, 22.4 l/mol): 0.3 % by volume is about 2143 mg/m3, i.e. more than the 1500 mg/m3 up to which the method was validated; the lower limit of 0.0012 % is about 8.6 mg/m3 (our conversion, assuming that the percentage is by volume and refers to standard conditions — the PCA document does not say so).

WHERE A SEEMINGLY CORRECT RESULT IS EASY TO GET. With sampling: condensation at any point of the line and too long a line leave no trace in the result — the standard requires a line as short as possible, sloping down towards the cooler and without condensation, and a probe, filter and line heated to 150 °C where necessary (6.1). With the container: a leaking bag or canister, or one made of a material that interacts with the gas, changes the sample between sampling and analysis; the pump must be gas-tight and the connections made of inert materials (6.1). With the canister and the ampoule: insufficient evacuation (the residual pressure is to be 10–20 hPa) dilutes the sample with the remaining gas. With units: a result in percent by volume, in mg/m3 under standard conditions, in dry gas or at reference oxygen are different quantities (Clause 4) — without stating the conditions the numbers cannot be compared. With the range: a result above 1500 mg/m3 lies outside the validation range (1).

WHAT WE DO NOT GIVE. We did not read 6.2, Clauses 7–11 or the annexes, so we do not give the columns and chromatographic conditions, operating and reference gases, sampling time, calibration procedure, calculations, interferences, quality control procedures or performance characteristics (repeatability, uncertainty). Nor do we give the requirements of regulations on methane emissions.

Method principle

Waste gas is taken from the duct with a probe (heated if necessary) through a particle filter and a cooler or permeation dryer into a gas-tight container — bag, glass ampoule or canister — or led directly to the sampling loop of the chromatograph. Part of the sample is introduced into a gas chromatograph, methane is separated on a packed or capillary column and determined with a flame ionisation detector against a reference gas of known composition; the result is converted to the mass concentration under standard conditions, in dry gas or at reference oxygen.

Applications

• Waste gases from stationary sources — methane concentration, method validated up to 1500 mg/m3 (1)
• Independent method (SRM according to EN 14181) — e.g. calibration and validation of permanently installed analysers (1, notes)
• Methane sources named in the introduction: landfills, composting plants, biogas and natural gas installations
• Waste gases — sampling for the determination of methane and methane emission, at one laboratory also the GC-FID concentration, in the accreditation scopes of 4 laboratories in PCA

Key parameters

Standard

Standard number

PN-EN ISO 25139:2011

Title (PL)

Emisja ze źródeł stacjonarnych — Manualna metoda oznaczania stężenia metanu z zastosowaniem chromatografii gazowej

Title (EN)

Stationary source emissions — Manual method for the determination of the methane concentration using gas chromatography

Step-by-step procedure

1. Sampling system

   Probe, filter, cooler, pump, container; line short, sloping, without condensation; heating to 150 °C if necessary. PN-EN ISO 25139:2011 current (PKN card as of 03.10.2026).

2. Sampling

   Into a bag (pump upstream of the bag or “lung principle”), into an ampoule or canister evacuated to 10–20 hPa, or directly into the sampling loop; we do not give the details (7.2).

3. Analysis

   Part of the sample into the gas chromatograph; separation on the column, FID detection; calibration with reference gas.

4. Calculations

   Mass concentration of methane under standard conditions, in dry gas or at reference oxygen (formulae in Clause 8 outside the sample).

5. Range

   A result above 1500 mg/m3 — outside the validation range of the method.

Required equipment and apparatus

Reagents, media and consumables

Health and safety (OHS)

• Methane is a flammable gas — keep samples and reference gases away from ignition sources
• Sampling on stacks and ducts — work at height, hot gases at probe and line components heated to 150 °C
• The flame ionisation detector requires hydrogen — handle cylinders and installations according to the rules for flammable gases

Frequently asked questions