Virginia Administrative Code
Title 9 - ENVIRONMENT
Agency 5 - STATE AIR POLLUTION CONTROL BOARD
Chapter 91 - REGULATIONS FOR THE CONTROL OF MOTOR VEHICLE EMISSIONS IN THE NORTHERN VIRGINIA AREA
Part X - Analyzer System Certification and Specifications for Enhanced Emissions Inspection Programs
Section 9VAC5-91-690 - Span gases; gases for calibration purposes

A. The gases used by emissions inspection stations in the emissions inspection shall be approved by the department and shall comply with the requirements of this section.

B. The gas concentrations, requirements, and tolerances of gases shall conform to the specifications contained in the EPA Technical Guidance document, EPA420-B-04-011, July 2004 (see 9VAC5-91-50) , and each container shall bear a bar-coded label containing concentration and tolerance information as required for calibration and audit purposes.

C. Gases shall be supplied in containers which meet all the provisions of the Occupational Safety and Health Administration as specified in 29 CFR 1910.101, Subpart H.

D. Gases shall be manufactured in accordance with the U.S. Environmental Protection Agency technical report, EPA-AA-TSS-83-8-B (see 9VAC5-91-50) .

E. The station owner shall maintain a comprehensive, up-to-date list provided by the department, including addresses and phone numbers, of gas blenders approved by the department.

F. Each analyzer instrument shall be permanently labeled with its optical correction factor (also referred to as "C" factor, propane equivalency factor, or propane to hexane conversion factor), carried to at least two decimal places (within the gas accuracy limits), e.g., (0.52). Factor confirmation shall be made on each assembled analyzer by measuring both N-hexane and propane on assembly line quality checks.