Soil Saturation Kit (% water in soil), 51169-100

General

The 51169-100 Soil Saturation Kit is designed to determine a soil's water percentage at saturation. Soil water content at saturation and bulk density are two of the most important parameters for many irrigation, geotechnical, and soil water movement applications. This kit reduces error by wetting the soil sample from the bottom and includes a stand so the apparatus can be placed on a balance.

The fixture included with the kit holds a HydraProbe Soil Sensor for accuracy validation and soil-specific calibration. Volumetric soil moisture is more comparable than gravimetric soil moisture because soil density can vary widely. In addition, volumetric soil moisture better reflects the volume of water applied by an irrigation cycle, so soil moisture is expressed as a volumetric water fraction or volumetric percent.

The soil water fraction by volume is expressed as θ = Vw/Vtot. The water volume Vw is determined from the weight of the wet soil minus the weight of the oven-dry soil. Because the wet soil cannot be weighed without the apparatus, wet soil weight is calculated by subtracting the apparatus weight and dry soil weight from the total weight of the apparatus holding the wet soil. Dry soil weight is determined by drying the sample for 24 hours at 100 degrees C.

The stand and water line connectors included in the kit ensure accurate wet-soil weight measurement on a balance. The weight of the stand, the probe, and the assembly are known and can be subtracted from the total weight. Soil must be wetted from the bottom so all air is pushed out the top. A reservoir and high-quality hoses are included to push water into the soil sample from the bottom. A stainless-steel ring with a known volume of 401 cc and screen mesh is included, and the stand allows the whole apparatus to be placed on a balance.

Applications and benefits

• Determination of soil water content at saturation.
• Irrigation, geotechnical, and soil water movement studies.
• Accuracy validation and soil-specific calibration with HydraProbe.
• Bottom-up wetting to expel trapped air and reduce error.
• Complete assembly weighing thanks to the included stand.