PURPOSE: To prevent mistakes in recognizing changes in flow rate by specifying a gas appliance now in use, and judging to which classification of heating values the heating value of the gas appliance belongs, the heating values being classified into plural portions in advance.
CONSTITUTION: An individual signal reception means 10 for receiving individual signals transmitted from each gas appliance being connected to a gas supply line is provided whereby flow rate signals from a flow rate measuring means 3 are separated from one another for each gas appliance. A supply heating value per unit time is calculated by a computing portion 7 for each gas appliance and is output to a classfication judging portion 8. The classfication of the supply heating value for each gas appliance is thus judged so as to obtain the supply heating value per unit time for each gas appliance and an aimed gas appliance can be specified even if plural gas appliances are started or stopped to be used simultaneously, and a change in flow rate can be dealt with with no mistake in recognizing it.
UNO TAKASHI
HORIIKE YOSHIO
IWABUCHI HIROO
