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Eliminating Bias
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Experience from implementing the Acid Rain Program has shown that CEM operators can eliminate bias from monitoring systems by instituting appropriate installation, operation, and quality assurance procedures. Certification test review has revealed that many sources could benefit from assistance in recognizing the physical and operational problems that produce systematic error and their available remedies.
The Operator’s Guide is designed to meet this need. Used as a reference document, the Guide makes it easier for CEM operators to improve monitor accuracy and meet regulatory requirements. We recommend browsing the entire Operator’s Guide to Eliminating Bias in CEM Systems (PDF) (122 pp., 1.1 MB) since it contains many internally cross-linked items. However, if your computer cannot support this, you can view individual chapters below.
The Guide is organized into eight chapters:
- Introduction and Table of Contents (PDF) (11 pp., 75 K)
- Chapter 1 (PDF): (12 pp., 109 K) describes the history and the engineering and statistical basis for the bias test.
- Chapters 2 through 7 provide describe in detail problems that can cause systematic measurement error and remedies that can be taken to address those problems. Chapters begin with a table summarizing the problems to be discussed.
Chapter 2 (PDF): (14 pp., 160 K) Probe Location and Stratification - Chapter 3 (PDF): (15 pp., 456 K) Extractive Sampling Systems
- Chapter 4 (PDF): (13 pp., 137 K) In-Situ Gas Monitoring Systems and Opacity Monitors
- Chapter 5 (PDF): (8 pp., 77 K) Flow Monitors
- Chapter 6 (PDF): (15 pp., 238 K)
- Gas Analyzers Chapter 7 (PDF): (10 pp., 49 K) Data Acquisition and Handling Systems Poster (PDF): (9 pp., 95 K) Cross-reference of all the problems discussed in chapters 2-7
- Chapter 8 (15 pp., 116 K) discusses elements that should be incorporated into ongoing Quality Assurance Programs to detect and prevent the problems that produce systematic error in monitor measurements