Two-wire RADAR sensor with intermittently operating circuitry components

US6014100A · kind A · utility

Assignee

• VEGA Grieshaber KG · DE

Inventors

• Josef Fehrenbach · Lenzkirch, DE
• Karl Griesbaum · Mühlenbach, DE

Key dates

• Filing date: Feb 27, 1998
• Grant date: Jan 11, 2000
• Expiry date: Feb 27, 2018

Classification

• Technology area (CPC G): Physics
• CPC primary: G01S13/88
• WIPO field: Measurement
• WIPO sector: Instruments

Abstract

An improved RADAR sensor for measuring the level of material utilizes conventional medium- or high-power microwave transmitter and microwave receiver devices, while utilizing only the relatively small amount of current supplied by a conventional low current two-wire process control loop. A transmit/receive unit and a control unit are operated intermittently to generate readings, and are set to a current-saving or even currentless standby mode between these periods of active measurement. During the inactive standby period, circuit components such as capacitors collect and store power to be used for the comparably high-power requirement during the active measurement cycles. The inactive standby periods are preferably long compared to the duration of the measurement periods. This permits operation with power entirely supplied from a common two-wire 4-20 mA process control loop.