DISCUSSION OF CALIBRATION ON NUCLEAR METERS FOR MEASURING MOISTURE AND DENSITY
The calibration is outlined, of a scintillation-type neutron-moisture meter designed to avoid materials containing neutron absorbers. Artificial materials such as bentonite, silica sand, and sodium metaphosphate were used to adjust densities; water and sugar were added to provide the moderation component. When the calibration curve was used to predict the water content in a marine clay, a serious discrepancy was found amounting to 6 lb of water per cu ft. A new calibration curve was then determined for the marine clay (illustrated). Subsequent chemical analysis showed that this particular soil contained about 1 percent potassium and 7 percent iron (by weight) which accounted for an 11 percent reduction in thermal neutron activity by absorption. One must, therefore, understand the factors that affect calibration, and the feasibility is questioned of using one calibration for all soils.
-
Supplemental Notes:
- Presented at the 66th Conference of the American Society of Testing and Materials.
-
Corporate Authors:
American Society for Testing and Materials (ASTM)
100 Barr Harbor Drive, P.O. Box C700
West Conshohocken, PA United States 19428-2957 -
Authors:
- Burn, K N
- Conference:
- Publication Date: 1965
Media Info
- Features: Figures;
- Pagination: p. 42-43
Subject/Index Terms
- TRT Terms: Bentonite; Calibration; Chemical analysis; Density; Inorganic phosphates; Moisture content; Nuclear gauges; Scintillation counters; Silica sands; Sodium inorganic compounds
- Old TRIS Terms: Sodium phosphate
- Subject Areas: Geotechnology; Highways;
Filing Info
- Accession Number: 00081225
- Record Type: Publication
- Report/Paper Numbers: STP 35 Conf Paper
- Files: TRIS
- Created Date: Mar 26 1975 12:00AM