MEASUREMENT BY MEANS OF ELECTRICAL CAPACITY OF THE MOISTURE CONTENT OF AGGREGATES ON A CONVEYOR BELT

MESURE PAR CAPACITE ELECTRIQUE DE LA TENEUR EN EAU DES GRANULATS SUR BANDE TRANSPORTEUSE

The very high frequency capacitive method is a technique which can be used for the continuous surveillance of the moisture content of aggregates. It is economical, simple and more reliable than the resistivity method. The method is based on the measurement of the apparent dielectric permittivity of wet material. In practice, a probe, comprised of two electrodes, is introduced into the wet material, thus forming a condenser with which the capacity is measured at very high frequency. An electronic system linked with the probe facilitates the automatic processing of the variation in capacity as a function of the moisture content. The calibration of the system was carried out at a concrete plant and at a testing station for highway components in Blois. The precision obtained leads to envisage a fairly wide use in the highway field. /TRRL/

• Authors:
  • Ranguin, C
  • Tran, N L
  • Jallet, A
• Publication Date: 1975-3

Language

• French

Media Info

• Features: Figures; Photos; References;
• Pagination: p. 97-100
• Serial:
  • Moniteur des Travaux Publics et du Batiment
  • Issue Number: 12

Subject/Index Terms

• TRT Terms: Aggregates; Automatic control; Automation; Bituminous mixtures; Calibration; Capacitance; Concrete; Continuous structures; Conveyors; Electrical equipment; Electricity; Electrodes; Electronics; Frequency (Electromagnetism); Measurement; Mix design; Mixing plants; Moisture content; Sensors; Surveillance
• ITRD Terms: 4577: Aggregate; 3882: Automatic; 4967: Bituminous mixture; 6171: Calibration; 6917: Capacity (electr); 4755: Concrete; 9006: Continuous; 6954: Electricity; 6951: Electrode; 6965: Electronics; 6997: Frequency; 4714: Mix design; 3648: Mixing plant; 5920: Moisture content; 6120: Sensor; 9101: Surveillance
• Subject Areas: Construction; Geotechnology; Highways; I36: Aggregates; I50: Construction and Supervision of Construction;

Filing Info

• Accession Number: 00163118
• Record Type: Publication
• Source Agency: Transport and Road Research Laboratory (TRRL)
• Report/Paper Numbers: Analytic
• Files: ITRD, TRIS
• Created Date: Mar 14 1978 12:00AM