Where is the minimum sampling frequency by section and material specified?

The minimum sampling frequency by section and material is detailed in the Materials Sampling Manual. This manual serves as a primary reference for guidelines related to the collection of materials, ensuring that the inspection process maintains consistency and adheres to predefined standards across various types of construction materials. It enables inspectors to understand the required frequency for obtaining samples, which is crucial for evaluating the quality and compliance of materials used in construction projects.

The other references may contain important information relevant to their specific topics, such as concrete inspection procedures or quality assurance protocols, but they do not specifically delineate the minimum sampling frequencies as explicitly as the Materials Sampling Manual does. This makes the manual the definitive source for this particular aspect of inspection practice.