Preliminary Performance Specification 001 (pdf, 18pp., 50kB) for ammonia (NH3) Continuous Emissions Monitoring Systems (CEMS) is now available from US EPA. It’s also available on the Environmental Measurement Center Preliminary Methods website.
Note that states regulate ammonia at their discretion—there are no Federal rules for ammonia emissions from stationary sources. The use of this document is left totally to the discretion of the regulatory authority. States may decide to use Preliminary Performance Specification 001, or their own procedures for validating ammonia CEMS.