TITLE
Technical Assistance Document, Performance Audit Procedures for
Opacity Monitors

AUTHOR(S)
Thomas J. Logan, Keith R. Hazel, Steven J. Plaisance, James W.
Peeler

PERFORMING ORGANIZATION NAME AND ADDRESS
Keith R. Hazel, Entropy Environmentalists, Inc.
Research Triangle Park, NC 27709


SPONSORING AGENCY NAME AND ADDRESS
Thomas J. Logan, U.S. Environmental Protection
Agency/AREAL/MRDD/SMRB (MD-77A)
Research Triangle Park, NC 27711


ABSTRACT
This manual contains monitor-specific performance audit procedures
and data forms for use in conducting audits of installed continuous
opacity monitoring systems (COMSs).  General auditing procedures
and acceptance criteria for various audit criteria are delineated. 
Practical considerations and common problems encountered in
conducting audits are discussed, and recommendations are included
to optimize the successful completion of performance audits. 
Performance audit procedures and field data forms were developed
for the following opacity monitors:  (1) Lear Siegler Measurement
Controls Corporation Dynatron 1100M and MC2000; (2) Lear Siegler
Measurement Controls Corporation Model RM-41; (3) Lear Siegler
Measurement Controls Corporation Model RM-4; (4) Dynatron Model
1100; (5) Thermo Environmental Instruments, Inc. Model 400: (6)
Thermo Environmental Instruments, Inc. Model 1000A; (7) Thermo
Environmental Instruments, Inc. Model D-R280AV; (8) Enviroplan
Model CEMOP-281; (9) United Sciences, Inc. Model 500C; (10) Land
Combustion Model 4500; and (11) DataTest Models 900A and 900RM. 
The concise step-by-step format of the audit procedures promotes a
thorough evaluation of the quality of the monitoring data and the
reliability of the opacity monitoring program.  Generic audit
procedures have been included for use in evaluating COMSs with
multiple transmissometers and combiner devices.  In addition,
several approaches for evaluating the zero alignment or "clear-
path" zero response have been described.  Although the zero
alignment checks cannot usually be conducted during a performance
audit, the zero alignment procedures have been included because
this factor is fundamental to the accuracy of opacity monitoring
data.