The report presents the findings obtained from the field evaluation of commercially available HCl monitoring equipment at a municipal waste-fired boiler which was not equipped with HCl emission control equipment. The analyzers were operated continuously during a two-month test period. The measurement techniques employed by the HCl monitors evaluated were IR gas filter correlation, specific ion electrode, wet chemical colorimetric, dry reaction colorimetric, and gas membrane galvanic cell. Except for the gas membrane galvanic cell monitor, the HCl monitoring equipment produced effluent measurements that were in good agreement with concurrent reference measurements. The results comparing the continuous emission monitor data to the reference wet-chemistry measurement data do not indicate biases for any of the monitor measurement techniques because of analytical interferences present in the effluent of this municipal refuse-fired boiler. Also, both in-stack dilution systems and the nondilution, heat-traced sampling system were found to reliably provide representative effluent samples to the analyzers.