Abstract: A probe relies on multiple sensors, which are capable of directly measuring soil moisture, temperature, and electrical conductivity (EC). The proposed probe uses radio frequency (“RF”) transformers to sense changes in load by the primary of the transformer, which will make direct contact with the soil. The probe contemplated herein, accurately measures EC values in liquids, and water saturated soils, by having direct contact with the medium in which the measurements are made. The measurements yield absolute EC, in any soil type.

Abstract: A probe relies on multiple sensors, which are capable of directly measuring soil moisture, temperature, and electrical conductivity (EC). The proposed probe uses radio frequency (“RF”) transformers to sense changes in load by the primary of the transformer, which will make direct contact with the soil. The probe contemplated herein, accurately measures EC values in liquids, and water saturated soils, by having direct contact with the medium in which the measurements are made. The measurements yield absolute EC, in any soil type.

Abstract: A probe relies on multiple sensors, which are capable of directly measuring soil moisture, temperature, and electrical conductivity (EC). The proposed probe uses radio frequency (“RF”) transformers to sense changes in load by the primary of the transformer, which will make direct contact with the soil. The probe contemplated herein, accurately measures EC values in liquids, and water saturated soils, by having direct contact with the medium in which the measurements are made. The measurements yield absolute EC, in any soil type.

Abstract: An RF control system characterized by the use of remotely located low profile radio frequency antennas which are concealed in conventionally appearing valve boxes or similar housings. The system includes a central control station, including a central RF transmitter, and a plurality of remote station, each including an RF receiver and antenna. A preferred remote station includes a valve box or similar housing of the type intended to be at least partially buried in the earth. The housing has a peripheral wall defining an access opening and a removable cover for bridging the opening. A directional discontinuity ring radiator (DDRR) antenna is physically mounted in the valve box housing on the interior side of the cover and is connected to a receiver, preferably also physically mounted on the cover.

Abstract: An intrusion detection system employing multiple bistatic microwave links and wireless means for remotely interrogating each link to provide alarm and status information at a central station. The central station includes a microprocessor for remotely adjusting the operating parameters of the microwave transmitters and receivers forming said links to increase the probability of intrusion detection and reduce the probability of false alarms.

Abstract: An intrusion detection system employing multiple bistatic microwave links and wireless means for remotely interrogating each link to provide alarm and status information at a central station.

Abstract: A system for hearing impaired persons for nonaudibly signalling the occurrence of monitored events such as an audible event (e.g. a baby crying), a telephone line signal, a switch closure, or a transducer output. The system includes a receiver module for producing a nonaudible signal responsive to an RF signal command, modulated by both a common and an identification frequency tone, received from one or more transmitter modules, each monitoring a predetermined set of events. The receiver and transmitter modules are configured to consume sufficiently low electric power to enable them to be battery energized. Battery energization permits the receiver module to be packaged in a pocket sized portable unit which the hearing impaired person can carry with him in his normal daytime activities.