Electricity: measuring and testing – Impedance – admittance or other quantities representative of... – Distributive type parameters
Patent
1996-05-30
1998-10-06
Brown, Glenn W.
Electricity: measuring and testing
Impedance, admittance or other quantities representative of...
Distributive type parameters
324643, 324694, G01N 2712
Patent
active
058182411
ABSTRACT:
Moisture sensing apparatus that uses slow wave transmission lines. Such transmission lines include a helically wound inner core, a surrounding outer conductor, and a moisture bearing material between the inner core and the outer conductor. Preferably, the transmission line includes a moisture barrier that separates the transmission line into a sealed dry section and a wet section which is in moisture communication with its environment. The moisture sensing apparatus further includes a source of electrical signals on the transmission line, and a moisture sensing circuit, operatively connected to the slow wave transmission line, which senses the moisture content of the moisture bearing material from the velocity of the impressed electrical signals on the slow wave transmission line. Preferably, the velocity of the impressed electrical signals is obtained indirectly using a sing-around measurement technique.
REFERENCES:
patent: 2752586 (1956-06-01), Jordan
patent: 3068404 (1962-12-01), Moore et al.
patent: 3703829 (1972-11-01), Dougherty
patent: 3965416 (1976-06-01), Friedman
patent: 3987362 (1976-10-01), McCann et al.
patent: 4786857 (1988-11-01), Mohr et al.
patent: 4949076 (1990-08-01), Wann
patent: 5445178 (1995-08-01), Fever
"A New Instrument for the Measurement of Liquid Level" The Review of Scientific Instruments, vol. 41, pp. 1083-1087, Jul. 1970 (Lindstrom et al.).
"Electromagnetic Determination of Soil Water Content: Measurements in Coaxial Transmission Lines," Topp et al. pp. 574-582, Water Resources, vol. 16, Jun. 1980.
"A Method of Measuring Soil Moisture By Time-Domain Reflectometry," Lediev et al, Journal of Hydrology, pp. 319-328, 1986 (Month Unavaiable).
"Soil Moisture Measurement Using Portable Dielectric Probes and Time Domain Reflectometry," Brisco Et al. Water Resources Research, vol. 28, pp. 1339-1346, May 1992.
"Soil Moisture Sensors for Continuous Monitoring," Amer etal., Water Resources Bulletin, pp. 69-83 , vol. 30, Feb. 1994.
"Calibrating Resistance--Type Soil Moisture Units in a High-Clay-Content Soil," Reynolds et al., Soil Science, vol. 144 pp. 237-241, Oct. 1987.
Sales Information Sheet for Water Content Reflectometer Model CS615-L, Campbell Scientific, Inc. Logan Utah, Dec. 1995.
LandOfFree
Moisture sensor using helical transmission line does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Moisture sensor using helical transmission line, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Moisture sensor using helical transmission line will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-82301