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The neutronic method for measuring soil moisture; La methode neutronique de mesure de l'humidite des sols

Abstract

The three group diffusion theory being chosen as the most adequate method for determining the response of the neutron soil moisture probe, a mathematical model is worked out using a numerical calculation programme with Fortran IV coding. This model is fitted to the experimental conditions by determining the effect of different parameters of measuring device: channel, fast neutron source, detector, as also the soil behaviour under neutron irradiation: absorbers, chemical binding of elements. The adequacy of the model is tested by fitting a line through the image points corresponding to the couples of experimental and theoretical values, for seven media having different chemical composition: sand, alumina, line stone, dolomite, kaolin, sandy loam, calcareous clay. The model chosen gives a good expression of the dry density influence and allows {alpha}, {beta}, {gamma} and {delta} constants to be calculated for a definite soil according to the following relation which gives the count rate of the soil moisture probe: N = ({alpha} {rho}{sub s} +{beta}) H{sub v} +{gamma} {rho}{sub s} + {delta}. (author) [French] La theorie a trois groupes etant choisie comme le moyen le plus adequat pour determiner la reponse de l'humidimetre, une mise en forme d'un modele mathematique est effectuee grace  More>>
Authors:
Couchat, Ph [1] 
  1. Commissariat a l'Energie Atomique, Cadarache (France). Centre d'Etudes Nucleaires
Publication Date:
Jul 01, 1967
Product Type:
Technical Report
Report Number:
CEA-R-3298
Resource Relation:
Other Information: 34 refs
Subject:
46 INSTRUMENTATION RELATED TO NUCLEAR SCIENCE AND TECHNOLOGY; DATA PROCESSING; HUMIDITY; MATHEMATICAL MODELS; MOISTURE; MOISTURE GAGES; MULTIGROUP THEORY; NEUTRON DETECTORS; NEUTRON DOSIMETRY; NEUTRON FLUX; PARAMETRIC ANALYSIS; SOILS
OSTI ID:
20726934
Research Organizations:
CEA Cadarache, 13 - Saint-Paul-lez-Durance (France)
Country of Origin:
France
Language:
French
Other Identifying Numbers:
TRN: FR06R3298038379
Availability:
Available from INIS in electronic form
Submitting Site:
FRN
Size:
[31] pages
Announcement Date:
May 30, 2006

Citation Formats

Couchat, Ph. The neutronic method for measuring soil moisture; La methode neutronique de mesure de l'humidite des sols. France: N. p., 1967. Web.
Couchat, Ph. The neutronic method for measuring soil moisture; La methode neutronique de mesure de l'humidite des sols. France.
Couchat, Ph. 1967. "The neutronic method for measuring soil moisture; La methode neutronique de mesure de l'humidite des sols." France.
@misc{etde_20726934,
title = {The neutronic method for measuring soil moisture; La methode neutronique de mesure de l'humidite des sols}
author = {Couchat, Ph}
abstractNote = {The three group diffusion theory being chosen as the most adequate method for determining the response of the neutron soil moisture probe, a mathematical model is worked out using a numerical calculation programme with Fortran IV coding. This model is fitted to the experimental conditions by determining the effect of different parameters of measuring device: channel, fast neutron source, detector, as also the soil behaviour under neutron irradiation: absorbers, chemical binding of elements. The adequacy of the model is tested by fitting a line through the image points corresponding to the couples of experimental and theoretical values, for seven media having different chemical composition: sand, alumina, line stone, dolomite, kaolin, sandy loam, calcareous clay. The model chosen gives a good expression of the dry density influence and allows {alpha}, {beta}, {gamma} and {delta} constants to be calculated for a definite soil according to the following relation which gives the count rate of the soil moisture probe: N = ({alpha} {rho}{sub s} +{beta}) H{sub v} +{gamma} {rho}{sub s} + {delta}. (author) [French] La theorie a trois groupes etant choisie comme le moyen le plus adequat pour determiner la reponse de l'humidimetre, une mise en forme d'un modele mathematique est effectuee grace a un programme de calcul numerique ecrit en code Fortran IV. Cette representation est adaptee a l'experience par l'etude de l'influence de parametres du systeme de mesure: tubage, source, detecteur, et du comportement du sol vis-a-vis des neutrons: presence d'absorbeurs, liaison chimique des elements. La validite du modele est testee par ajustement d'une droite aux points images des couples de valeurs experimentales et theoriques, ceci pour sept milieux distincts definis par leur composition chimique: sable, alumine, calcaire, dolomie, kaolin, limon sableux, argile calcaire. Le modele prevoit, bien l'influence de la densite seche et permet de calculer pour un sol donne les constantes {alpha}, {beta}, {gamma} et {delta} intervenant dans la formule qui donne la vitesse de comptage de l'humidimetre soit: N = ({alpha} {rho}{sub s} +{beta}) H{sub v} +{gamma} {rho}{sub s} + {delta}. (auteur)}
place = {France}
year = {1967}
month = {Jul}
}