This method covers the measurement of total water content of fresh concrete. It consists of drying a test specimen of fresh concrete using a relatively high-power microwave oven within a short period of time. The difference in mass between the fresh and dry concrete test specimen will be the water content of that test specimen. Water content per unit volume of concrete can be determined by knowing the unit weight of that concrete. Unit weight shall be determined in accordance with T 121M/T 121 or ASTM C 138/C 138M. This standard is applicable to both laboratory and field tests as long as a power source is available. This standard may involve hazardous materials@ operations@ and equipment. This standard does not purport to address all of the safety concerns associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.