Pneumatic sensors are used to measure the air permeability of the soil. It is a standard technique for the measurement of soil porosity in the field and laboratory by applying a pressure gradient across a sample or region and monitoring the air flow. For PSS, pneumatic sensing is typically based on compressed air forced through an outlet in a tillage implement that is pulled through the soil. Permeability is measured using changes in pressure under constant flow.
Air permeability can be used to infer properties such as soil structure, soil type and water content.
On-the-go measurement of air permeability using a compressed air system and outlet mounted in a soil shank [1] [2].
Research.
1. Clement, B.R., Stombaugh, T.S., 2000. Continuously-measuring soil compaction sensor development. ASAE Paper No. 001041. ASAE, St. Joseph, MI.
2. Koostra, B.K., Stombaugh, T.S., 2003. Development and evaluation of a sensor to continuously measure air permeability of soil. ASAE Paper No. 031072. ASAE, St. Joseph, MI.