Eliminating Bias in Monitoring Systems
The Acid Rain Program experience has shown that continuous emissions monitoring system (CEMS) operators can eliminate bias from monitoring systems by instituting appropriate installation, operation, and quality assurance procedures. An Operator’s Guide to Eliminating Bias in CEM Systems provides information recognizing the physical and operational problems that produce systematic error and their available remedies.
The Guide makes it easier for CEMS operators to improve a monitor's accuracy and meet regulatory requirements. We recommend viewing the entire individual chapters.
The Guide is organized into eight chapters:
- Chapter 1 describes the history and the engineering and statistical basis for the bias test.
- Chapters 2 through 7 describe problems that can cause systematic measurement error and remedies that can be taken to address those problems. Each chapter includes a table summarizing the problems discussed in that chapter.
- The Checklist provides a cross-reference of all the problems discussed in these chapters.
- Chapter 8 discusses elements that should be incorporated into ongoing quality assurance programs to detect and prevent the problems that produce systematic error in monitor measurements.
For more emissions monitoring resources, return to Emissions Monitoring and Reporting.
- An Operator's Guide To Eliminating Bias In CEM Systems (pdf)
- Introduction and Table of Contents (pdf)
- Chapter 1: Overview: Accuracy, Precision, and Bias in Continuous Emission Monitoring Systems (pdf)
- Chapter 2: Bias Due to Probe Location and Stratification (pdf)
- Chapter 3: Sources of Bias in Extractive CEM Systems (pdf)
- Chapter 4: Sources of Bias in In-Situ Monitoring Systems (pdf)
- Chapter 5: Sources of Bias in Flow Monitoring Systems (pdf)
- Chapter 6: Sources of Bias in the Gas Analyzer (pdf)
- Chapter 7: Sources of Bias in the Data Acquisition and Handling System (pdf)
- Poster: Eliminating Bias in CEM Systems - A Checklist (pdf)
- Chapter 8: Bias and Quality Assurance Programs (pdf)