1. Prepare cold boiled water (there is no air in the water), boil tap water for 20 minutes, and let it cool for later use.
2. Exhaust the clay head, unscrew the top end cap, unplug the silicone plug, pour in cold water, fill it up, stand the instrument upright for 10-40 minutes (without a cover), and see water dripping from the surface of the clay head, then Plug the silica gel plug and wrap the clay head with a paper towel to absorb water so that the soil tension reaches about -40kpa. If you see bubbles rising, you can also shake the device to exhaust as much as possible. Repeat this process 2-3 times.
3. Submerge the clay head in the water, wait for the soil tension to return to within -10kpa, fill up again with water, plug the silica gel plug, screw on the top end cap, and set aside.