U.S. flagAn official website of the United States government
                    Here's how you know **Official websites use .gov**
                            
                            A **.gov** website belongs to an official government organization in the United States.
 **Secure .gov websites use HTTPS**
                            
                            A **lock** (                            
                              A locked padlock                                                      
                            
                            ) or **https://** means you’ve safely connected to the .gov website. Share sensitive information only on official, secure websites.


Menu Agricultural Research Service
						
                    U.S. DEPARTMENT OF AGRICULTURE
 Cotton Production and Processing Research: Lubbock, TX
 close



    Research

                    Research Projects
                                    Publications
                                    Collaborations
                                    News
                People

                    Staff Listing
                                    CareersSearch small
                    Search
            
            ARS Home
                                About ARS
                                Contact Us




ARS Home Plains Area Lubbock, Texas Cropping Systems Research Laboratory Cotton Production and Processing Research Research Publications at this Location





- ARS National Programs
- Search for a scientific manuscript
- Search for a research project
- ARS Software
- Programs and Projects
- Collaborations
- Subjects of Investigation
- Publications

Title:   Author  item
                                            Pelletier, Mathewitem
                                            Schwartz, Robertitem
                                            Holt, Gregoryitem
                                            Wanjura, Johnitem
                                            Green, Timothy
  Submitted to: Agriculture
                                    Publication Type: Peer Reviewed Journal
                                    Publication Acceptance Date: 11/5/2016
                                    Publication  Date: 11/11/2016
                                    Citation: Pelletier, M.G., Schwartz, R.C., Holt, G.A., Wanjura, J.D., Green, T.R.Frequency domain probe design for high frequency sensing of soil moisture. Agriculture. 6(4):60-72. 2016.Interpretive Summary: This research reports on the development of an embedded microwave moisture sensing probe that is designed to provide high accuracy results to aid in the establishment of laboratory grade reference standards. The work established that the new probe has superior performance with regard to preservation of the probe's signal integrity, which allows the sensor to extend the typical operating from below 1GHz to above 6 GHz. This wider frequency range opens up the potential for using the probe in low permittivity media, such as seedcotton and cotton lint, that previously didn't provide a strong enough response at the lower frequencies the previous probe design was limited to. In the development of the probe, new techniques were also developed to remove the effects of impedance mismatch from the readings. The correction of impedance mismatch further improves the accuracy of the obtained measurements which is significant for materials that cover a wide span of permittivities as the moisture content changes from dry to saturated conditions that cause the impedance to exhibit a strong impedance mismatch across a significant portion of the moisture regime.
                                Technical Abstract: Accurate moisture sensing is an important need for many research programs as well as in control of industrial processes. This paper covers the development of a frequency domain sensing probe for use in obtaining measurements of material properties suitable for work ranging from 0 to 6GHz. The probe was developed to cover a wide range of permittivities ranging from a low permittivity of 2.5 to elevated permittivities in excess of 40. Due to such a wide range of permittivities, a 50 Ohm probe was impossible to design, so algorithms were developed to correct for the impedance mismatches along with calibration techniques to obtain an accurate measurement of material that is independent from the probe design.


Return to top


Connect with ARS Sign up


ARS Home
                            USDA.gov
                            Plain Writing
                            Policies & Links
                            Civil Rights Statements
                            FOIA
                            Accessibility Statement
                            Privacy Policy
                            Non-Discrimination Statement
                            Quality of Information
                            USA.gov
                            WhiteHouse.gov