Title:
【発明の名称】工業用タンク等の充てんレベル測定装置のための電気回路
Document Type and Number:
Japanese Patent JPH05505470
Kind Code:
A
Abstract:
PCT No. PCT/EP92/00131 Sec. 371 Date Oct. 8, 1992 Sec. 102(e) Date Oct. 8, 1992 PCT Filed Jan. 21, 1992 PCT Pub. No. WO92/14124 PCT Pub. Date Aug. 20, 1992.An electrical device for measuring the liquid level in industrial tanks and the like with a microwave transmitter and receiver and a waveguide provided with an aperture and an antenna. The signal reflected from the liquid surface and the transmitted signal are fed to a frequency conversion stage (8), whose low-frequency output signal is sent via an A/D converter (12) to a microprocessor calculating the fill level. To reduce the effect of interference frequencies produced by reflection of microwaves in the optical aperture, etc., a band-pass filter (9,10) with a lower limiting frequency selected to attenuate the low-frequency interference frequencies is placed between the frequency conversion stage (8) and the A/D converter (12). The lower limiting frequency can either be controlled with microprocessor (13) or the band-pass filter (9, 10) has adjustable limiting frequencies. To inhibit overcontrol of the A/D converter, an amplification stage (11) controlled by microprocessor (13) is provided for band-pass filter (9, 10).
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Inventors:
Van der Paul, Ronald
Application Number:
JP50276792A
Publication Date:
August 12, 1993
Filing Date:
January 21, 1992
Export Citation:
Assignee:
Krone Mestehinik Gezershyaft Mitz Besilyenktel Haftung Und Companie Commande Gezershyaft
International Classes:
G01F23/284; G01S7/295; G01S13/34; G01S13/88; (IPC1-7): G01S13/34; G01F23/28; G01S7/295
Attorney, Agent or Firm:
Toshio Yano (2 outside)