Skip to main content
Find a Lawyer

Code of Federal Regulations Title 40. Protection of Environment § 40.89.413 Raw sampling procedures

Current as of January 02, 2025 | Updated by Findlaw Staff

Follow these procedures when sampling for gaseous emissions.

(a) The gaseous emission sampling probe must be installed at least 0.5 m or 3 times the diameter of the exhaust pipe—whichever is the larger—upstream of the exit of the exhaust gas system.

(b) In the case of a multi-cylinder engine with a branched exhaust manifold, the inlet of the probe shall be located sufficiently far downstream so as to ensure that the sample is representative of the average exhaust emissions from all cylinders.

(c) In multi-cylinder engines having distinct groups of manifolds, such as in a “Vee” engine configuration, it is permissible to:

(1) Sample after all exhaust pipes have been connected together into a single exhaust pipe.

(2) For each mode, sample from each exhaust pipe and average the gaseous concentrations to determine a value for each mode.

(3) Sample from all exhaust pipes simultaneously with the sample lines connected to a common manifold prior to the analyzer. It must be demonstrated that the flow rate through each individual sample line is ±4 percent of the average flow rate through all the sample lines.

(4) Use another method, if it has been approved in advance by the Administrator.

(d) All gaseous heated sampling lines shall be fitted with a heated filter to extract solid particles from the flow of gas required for analysis. The sample line for CO and CO2 analysis may be heated or unheated.

Previous Part of Code Next Part of Code
Back to Chapter List

Cite this article: FindLaw.com - Code of Federal Regulations Title 40. Protection of Environment § 40.89.413 Raw sampling procedures - last updated January 02, 2025 | https://codes.findlaw.com/cfr/title-40-protection-of-environment/cfr-sect-40-89-413/

FindLaw Codes may not reflect the most recent version of the law in your jurisdiction. Please verify the status of the code you are researching with the state legislature before relying on it for your legal needs.

Was this helpful?

Welcome to FindLaw's Cases & Codes

A free source of state and federal court opinions, state laws, and the United States Code. For more information about the legal concepts addressed by these cases and statutes, visit FindLaw’s Learn About the Law.

Go to Learn About the Law

Latest Blog Posts

For Legal Professionals

Learn About The Law

Get help with your legal needs

FindLaw’s Learn About the Law features thousands of informational articles to help you understand your options. And if you’re ready to hire an attorney, find one in your area who can help.

Go to Learn About the Law

Need to Find an Attorney?

Search our directory by legal issue

Enter information in one or both fields (Required)

Copied to clipboard