The ASTM F2170-19a standard specifies a test method for determining the relative humidity of concrete floor slabs using in-situ probes. This method provides accurate data on the drying state of the floor slabs by performing Humidity measurement inside the concrete floor slabs. This test is essential for assessing the suitability of concrete floor slabs for the laying of floor coverings (e.g. floors, tiles, etc.), especially in ensuring the adhesion and long-term Stability of the flooring material. By using in situ Humidity probes, this method allows for the rapid and non-Destructiveness acquisition of accurate Humidity readings, providing a scientific basis for construction and maintenance work. This standard has important application value in the building, construction and flooring industries to ensure the long-term Reliability of building masses and flooring materials.