Title:
ELECTRIC HOT-WATER HEATER
Document Type and Number:
Japanese Patent JPH04317609
Kind Code:
A
Abstract:
PURPOSE: To exactly measure the liquid quantity by an ultrasonic wave.
CONSTITUTION: In a bottom part of a vessel 2, an ultrasonic sensor 5 for transmitting and receiving an ultrasonic wave is provided, and the time when the transmitted ultrasonic wave is reflected by the water surface 7 is measured plural times and when their measured value origin is held within a prescribed variance range, the liquid quantity is calculated by a liquid quantity arithmetic means. The time being proportional to the liquid quantity can be measured by the ultrasonic wave, and also, the liquid quantity is derived by deciding whether the water surface is stable or not, therefore, the liquid quantity can be measured with high accuracy.
Inventors:
TANAKA HIRONOBU
HAMADA KUNIO
YOSHIDA YUICHI
SHIMADA KAZUYUKI
HAMADA KUNIO
YOSHIDA YUICHI
SHIMADA KAZUYUKI
Application Number:
JP8384091A
Publication Date:
November 09, 1992
Filing Date:
April 16, 1991
Export Citation:
Assignee:
MATSUSHITA ELECTRIC IND CO LTD
International Classes:
A47J27/21; G05D9/00; G05D9/12; (IPC1-7): A47J27/21; G05D9/00; G05D9/12
Attorney, Agent or Firm:
Akira Kobiji (2 outside)