Preparation of Soil Sample and Preparation of Tensiometer for Analyzing Soil Health and Hydraulic Properties with Evaporation Experiments

To begin, remove the plastic cover from the flat edge side of the metal sampling core, and place a paper coffee filter on top, followed by a saturation plate. Saturate the soil samples for at least 24 hours inside the sample cores in a large plastic container with degassed deionized water. Invert the core and saturation plate into the container, and fill it with degassed deionized water, leaving a one centimeter space from the top of the soil sample.

Using a 20 milliliter syringe and fine-tip needle, fill both tensiometer shaft ports with degassed deionized water. Shine a light into the port and check for debris to confirm if the pressure transducer is clean. Place the acrylic top on the sensor unit and fasten the metal clips.

Insert the syringe containing degassed deionized water into the opening of the acrylic top and fill just below the top of the acrylic head. To attach the acrylic top to the degassing unit, connect the T tube on the degassing unit to the top of the acrylic head. Place stage mounted cups into both positions on the degassing unit, and fill three quarters of each cup with degassed deionized water.

Screw the tensiometers into the threaded acrylic holders, and adjust the black O ring to the top of the acrylic holder. Place the tensiometers into the degassed deionized water in the stage mounted cups. Turn on the vacuum pump until 0.4 bar is reached.

Then, turn off the vacuum pump and allow the system to equalize. Turn on the vacuum pump again until 0.8 bar is reached. After 24 hours, remove the tubing from the acrylic top and take out all tenters from the acrylic holders.

Place the short and tall tensiometers into separate beakers of degassed deionized water.