The Object of this Document is to specify and discuss the methods and instrumentation for testing boiler make-up and feedwater, steam, and condensate in relation to performance testing as may be required in Performance Test Codes in one-time acceptance testing and in continuous performance monitoring. This Document also provides guidance to power plant management, engineers, chemists, and operators in the design and operation of sampling systems for monitoring of cycle chemistry. The methods and equipment recommended herein may be useful for monitoring other influent and effluent streams of the power plant. Contamination of the stream and water cycle must be at or less than the maximum specified for the performance test before a turbine, condenser, or deaerator performance test is made.