ASME PTC 19.1 covers Measurement Uncertainty for all instruments. PTC 19.11 refers to 19.1 for uncertainty analysis but is specifically for steam/water sampling. Do not substitute one for the other.
PTC 19.11 - Steam and Water Sampling, Conditioning ... - ASME Asme Ptc 19.11 Pdf
This article provides a comprehensive deep dive into what ASME PTC 19.11 is, why it matters, how to obtain the official PDF, and how to apply its principles to prevent catastrophic equipment failure. ASME PTC 19
ASME publishes free "Interpretations" documents on their website. These are answers to specific technical questions about PTC 19.11—such as "How do we handle two-phase sampling at low flow?" While not a substitute for the PDF, they provide high-level guidance. PTC 19
: Provides design and operation guidelines for power plant chemists, engineers, and operators to manage cycle chemistry. System Protection
Without PTC 19.11, your ASME PTC 6 performance test is invalid. Period. If your water quality sampling is off by 2% conductivity, your heat rate calculation could be off by 0.5%—millions of dollars in fuel annually.
The code provides equations to correct impurity readings for background conductivity and temperature effects.