ASTM D6216 Opacity Monitor Requirements Explained
Opacity Monitor Learning Center
ASTM D6216 describes how manufacturers demonstrate that continuous opacity monitoring equipment meets specified design and performance requirements. For facilities evaluating a continuous opacity monitor, it helps explain the equipment certification behind an EPA PS-1 system.
What is ASTM D6216?
ASTM D6216 is a standard practice for manufacturer certification of opacity monitors. It addresses equipment design, calibration and performance testing. It also applies to organizations repairing, remanufacturing or reselling opacity monitoring equipment.
Its purpose is to establish dependable instrument performance before the monitor is put into service. The standard includes procedures for testing representative equipment designs and individual instruments. See ASTM’s official D6216-20 description and scope.
How does ASTM D6216 relate to EPA PS-1?
EPA PS-1, in 40 CFR Part 60, Appendix B, uses ASTM D6216 for the manufacturer’s design and performance requirements. PS-1 also addresses where the system is installed and how its performance is checked at the facility.
The current PS-1 text references ASTM D6216-20. Section 2.1 includes an exception from recertification to that edition for monitors initially certified before May 30, 2023 under the listed earlier editions. Review the equipment’s certificate and the current PS-1 provisions when evaluating an existing installation.
What equipment characteristics are evaluated?
The manufacturer’s checks include response time, calibration error, optical alignment and spectral response. Design evaluations also support the stated operating ranges for ambient temperature and supply voltage. A certificate of conformance documents the manufacturer’s evaluation; it does not replace the tests required after installation. The complete test methods and acceptance criteria are provided in ASTM D6216.
What should an owner or operator request?
- A certificate of conformance and supporting equipment documentation.
- Confirmation of the monitor configuration, optical path and intended operating conditions.
- A plan for the installed system’s PS-1 testing, including its recording and averaging functions.
- Current manuals and a service plan appropriate to the installation.
PS-1 requires the owner or operator to obtain the manufacturer’s certificate and evaluate the installed COMS. Manufacturer certification alone does not establish that the completed installation satisfies every applicable requirement. EPA’s PS-1 resource page provides the specification and supporting information.
Does ASTM D6216 replace daily checks or periodic audits?
No. Equipment certification and ongoing quality assurance serve different purposes. Where applicable, EPA Procedure 3 addresses ongoing COMS quality assurance. Establish the required checks and audit schedule using the applicable rule and facility permit.
How can EMS help?
The EMS WatchDog PS-1 continuous opacity monitor meets or exceeds EPA PS-1 and ASTM D6216. It combines double pass opacity and dust monitoring with a 5.7-inch color touchscreen, expanded trends and diagnostics, automatic daily calibration checks, and additional relays and outputs compared with the standard WatchDog.
EMS provides opacity monitor service, startup, certification and audit support. Request a WatchDog PS-1 quote with your process description, stack dimensions, permit requirements and existing equipment details.
Educational summary updated September 22, 2026. Sources: ASTM D6216-20, EPA PS-1, current eCFR Appendix B and EPA Procedure 3, linked above. Refer to the complete standards and applicable permit for your installation.