Soil Water Potential Sensor Using Volume-Changing Material
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing methods for sensing and measuring soil water potential are limited by their durability, cost-effectiveness, and responsiveness to subtle changes in soil water content.
Innovation Solution
A universal, durable, and cost-effective water potential effector apparatus comprising a water-permeable housing with a volume-changing material (VCM) that expands or contracts in response to changes in water potential, coupled with a compressible insert and a receiver to transduce signals.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If tensiometric methods are used to measure soil water potential, then direct reading and salinity resistance are achieved, but the soil suction range is limited to 0-100 kPa
Solution Approach 1:
The measurement range is segmented into multiple intervals, each handled by a different sensor type (tensiometers for 0-100 kPa, pressure membranes for higher ranges). This allows each sensor to operate within its optimal range while the system as a whole covers a broader spectrum of soil water potentials.
Solution Approach 2:
The system is designed to be universal by integrating multiple measurement approaches (tensiometric and pressure membrane methods) into a single platform that can handle various soil water potential ranges, making it adaptable to different soil types and irrigation requirements.
2Measurement precision
If direct measurement methods (thermo-gravimetric or thermo-volumetric) are used to determine soil water content, then accuracy is achieved (±0.01 ft³/ft³), but the measurement process is destructive, slow (2 days minimum), and time-consuming
Solution Approach 1:
The patent replaces destructive thermal processing (oven drying) with non-destructive mechanical sensing (tensiometric and pressure membrane measurements). This substitution enables real-time or near-real-time measurements without altering the soil sample, dramatically reducing measurement time from days to minutes or seconds.
Solution Approach 2:
The sensor system enables continuous, in-situ monitoring of soil water potential without requiring sample removal or laboratory processing. The soil profile autonomously provides measurement data through the installed sensors, eliminating the need for repeated destructive sampling and enabling ongoing surveillance of soil moisture conditions.
3Productivity
If indirect methods are used to monitor soil water content, then speed and non-destructiveness are achieved, but accuracy and reliability depend on calibration relationships with other measurable variables
Solution Approach 1:
The patent uses soil water potential (matric potential) as an intermediary physical quantity that directly reflects soil moisture status without requiring calibration against water content. By measuring the energy state of water in the soil rather than inferring it from other properties, the system achieves both speed and reliability, as the measurement is direct and physics-based rather than empirically calibrated.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The apparatus provides a fast response time and can detect subtle changes in soil water content, offering improved durability and cost-effectiveness compared to existing systems.
Implementation Method 1
a volume changing material (VCM) capable of retaining water, the VCM configured to increase or decrease its volume in response to changes in water potential of the water containing media
Implementation Method 2
the VCM configured to increase or decrease its volume in response to changes in water potential
Data Source
AI summary
An apparatus for effecting water potential in a water-containing media comprising a water-permeable housing, a volume changing material that can retain water, a compressible insert and a receiver for receiving and transducing a signal, is provided.