IODP Expedition 392 Moisture and Density

Moisture and density (MAD) data were acquired on ~10 mL sediment or rock samples by measuring three out of four material parameters: wet (saturated) mass, wet volume, dry mass, and/or dry volume after 24 h drying in a convection oven at 105 degrees C. From the moisture and volume measurements, the following phase relationships are calculated: wet and dry water content, wet bulk density, dry bulk density, grain density, porosity, and void ratio. The combination of measurements is defined by the submethod chosen: A, B, C, or D. Wet (A, B, or C) and dry (A, B, C, or D) mass is determined using motion-compensated balances. Wet volume is determined either by helium pycnometry (A) or by the sample's geometric dimensions using calipers (A or D). Dry volume (C or D) is measured by helium pycnometry. Submethods A and B are not recommended by IODP. Submethod C is suitable for saturated materials such as fine-grained sediments. Submethod D is suitable for unsaturated porous material such as certain limestones and basalts.含水率与密度（Moisture and Density, MAD）数据采集自约10 mL的沉积物或岩石样品，通过测定四项物性参数中的三项获得：湿（饱和）质量、湿体积、干质量，以及经105℃对流烘箱干燥24小时后的干体积（可按需组合其中三项）。基于含水率与体积的测定结果，可计算得到如下物相关系：湿基含水率、干基含水率、湿堆积密度、干堆积密度、颗粒密度、孔隙率及孔隙比。测定组合方式由所选子方法（A、B、C或D）确定。湿质量（对应子方法A、B或C）与干质量（对应子方法A、B、C或D）均采用运动补偿天平进行测定。湿体积可通过两种方式测定：氦气置换法（helium pycnometry，适用于子方法A），或使用游标卡尺测量样品几何尺寸（适用于子方法A或D）。干体积（对应子方法C或D）采用氦气置换法测定。国际大洋发现计划（International Ocean Discovery Program, IODP）不推荐使用子方法A与B。子方法C适用于饱和样品，例如细粒沉积物。子方法D适用于非饱和多孔介质样品，例如特定石灰岩与玄武岩。