Method 10
Determination of Carbon Monoxide Emissions From Stationary Sources (Instrumental Analyzer Procedure)
40 CFR Part 60, Appendix A-4
From the method — regulatory text
Sections 1.0 and 2.0 of Method 10—Determination of Carbon Monoxide Emissions From Stationary Sources (Instrumental Analyzer Procedure), as published at 40 CFR Part 60, Appendix A-4. Retrieved 10/07/2026. The full method is on the eCFR.
1.0 Scope and Application
What is Method 10?
Method 10 is a procedure for measuring carbon monoxide (CO) in stationary source emissions using a continuous instrumental analyzer. Quality assurance and quality control requirements are included to assure that you, the tester, collect data of known quality. You must document your adherence to these specific requirements for equipment, supplies, sample collection and analysis, calculations, and data analysis. This method does not completely describe all equipment, supplies, and sampling and analytical procedures you will need but refers to other methods for some of the details. Therefore, to obtain reliable results, you should also have a thorough knowledge of these additional test methods which are found in appendix A to this part:
(a) Method 1—Sample and Velocity Traverses for Stationary Sources.
(b) Method 4—Determination of Moisture Content in Stack Gases.
(c) Method 7E—Determination of Nitrogen Oxides Emissions from Stationary Sources (Instrumental Analyzer Procedure).
1.1 Analytes. What does this method determine? This method measures the concentration of carbon monoxide.
| Analyte | CAS No. | Sensitivity |
|---|---|---|
| CO | 630-08-0 | Typically <2% of Calibration Span. |
1.2 Applicability. When is this method required? The use of Method 10 may be required by specific New Source Performance Standards, State Implementation Plans, and permits where CO concentrations in stationary source emissions must be measured, either to determine compliance with an applicable emission standard or to conduct performance testing of a continuous emission monitoring system (CEMS). Other regulations may also require the use of Method 10.
1.3 Data Quality Objectives. Refer to section 1.3 of Method 7E.
2.0 Summary of Method
In this method, you continuously or intermittently sample the effluent gas and convey the sample to an analyzer that measures the concentration of CO. You must meet the performance requirements of this method to validate your data.
EssentialRegs notes
Our plain-English reading of Method 10. Not the method text.
What it measures
The concentration of carbon monoxide (CO) in stack gas, measured continuously by an instrumental analyzer.
How it works
A sample of stack gas is drawn continuously from the stack, conditioned to remove moisture and other interfering material, and passed to an analyzer that reads carbon monoxide. The analyzer works by infrared absorption, and the method requires that other gases in the stream, such as carbon dioxide and water vapor, do not distort the reading. Calibration gases of known concentration are used to set and check the analyzer.
Equipment
A nondispersive infrared (NDIR) carbon monoxide analyzer, a sampling probe and line, a moisture removal system, a data recorder and calibration gases.
When a rule cites it
Performance tests on engines, turbines, heaters, incinerators and other combustion equipment against a carbon monoxide limit. It is named where a rule needs a carbon monoxide concentration to show that combustion is complete.
Notes for compliance staff
Method 10 gives a concentration only. A limit stated at a reference oxygen level also needs an oxygen measurement, most often from Method 3A. Methods 10A and 10B are separate procedures with their own scopes, so a rule that cites one of them is not asking for Method 10.
Cited by
Provisions in the corpus whose text cites Method 10. Subscribers land on the provision in the regulation reader; visitors see a preview of it (the GP05 sample opens in full).
Regulation 4
40 CFR Part 60 Subpart JJJJ
- Table 2 to Subpart JJJJ of Part 60 — Requirements for Performance Tests
40 CFR Part 60 Subpart OOOO
40 CFR Part 60 Subpart OOOOa
40 CFR Part 60 Subpart OOOOb
40 CFR Part 60 Subpart OOOOc
40 CFR Part 63 Subpart ZZZZ
- Table 4 to Subpart ZZZZ of Part 63 — Requirements for Performance Tests
The sections marked as regulatory text above are reproduced from the CFR. Everything under ‘EssentialRegs notes’ is our reference copy, not the method. The method as published in the CFR controls.