Using a pressure chamber is worthwhile
A successful irrigation program needs to have three sources of information: how much water is needed in a year, how much water the soil currently has stored, and whether the plant needs water. Most irrigation programs use the first two components, however most irrigators ignore the last component, which also happens to be the most important. Retired farm advisor Allan Fulton explains more:
https://www.sacvalleyorchards.com/manuals/stem-water-potential/using-a-pressure-chamber-is-worthwhile/