POLYMER CAPACITANCE SENSORS FOR MEASURING SOIL GAS HUMIDITY IN DRIER SOILS

This study assessed polymer capacitance sensors for measuring soil gas relative humidity (RH) and total suction in soils that are too dry for thermocouple psychrometers. Capacitance of the sensors varies as the RH of the gas surrounding the sensor is varied. Soil gas RH is inferred through a calibration curve relating soil gas RH and capacitance. Tests conducted with 6 finer textured soils and 3 sands showed that the capacitance sensors can be used to obtain unbiased estimates of RH for a broad variety of soils with a precision of ~+/- 3%. Tests also showed the sensors are non-hysteretic and relatively insensitive to temperature, except when the temperature approaches the freezing point of water. An example is given illustrating how capacitance sensors can be used to monitor soil gas RHs in alternative earthen final covers that employ passive flow of atmospheric air to remove water.

• Availability:
  • Find a library where document is available. Order URL: http://worldcat.org/issn/01496115
• Corporate Authors:

  ASTM International

  100 Barr Harbor Drive
  West Conshohocken, PA  United States  19428-2959
• Authors:
  • Albrecht, B A
  • Benson, C H
  • Beuermann, S
• Publication Date: 2003-3

Language

• English

Media Info

• Features: Figures; Photos; References; Tables;
• Pagination: p. 3-11
• Serial:
  • Geotechnical Testing Journal
  • Volume: 26
  • Issue Number: 1
  • Publisher: ASTM International
  • ISSN: 0149-6115
  • EISSN: 1945-7545
  • Serial URL: https://www.astm.org/products-services/standards-and-publications/geotechnical-testing-journal.html

Subject/Index Terms

• TRT Terms: Foundation soils; Geotechnical engineering; Humidity; Psychrometers; Sensors; Soil science; Soil suction; Soil tests; Thermocouples
• Subject Areas: Geotechnology; Highways; I42: Soil Mechanics;

Filing Info

• Accession Number: 00943732
• Record Type: Publication
• Files: TRIS
• Created Date: Jun 17 2003 12:00AM