Abstract: A method and apparatus are described for controlling demand of a fluid. The method includes measuring a fluid supply pressure in a supply pipe, determining that the fluid supply pressure is lower than a predetermined threshold supply pressure, and directing a control signal from the fluid information unit to the,one or more demand control units to reduce demand for the fluid. In addition, a method and apparatus are described for measuring density of a fluid flowing through a demand pipe. The method includes determining that fluid flow through the demand pipe is stable, measuring fluid flow rate through the demand pipe, preventing the fluid from flowing into the demand pipe for a sample period of time, measuring a drop in fluid pressure in the demand pipe during the sample period, and determining the density from the measured pressure drop. Also, a utility meter for metering a fluid flowing through a supply pipe and a demand pipe having an audible indicator to provide an audible signal to a user is described.

Abstract: A method and apparatus are described for controlling demand of a fluid. The method includes measuring a fluid supply pressure in a supply pipe, determining that the fluid supply pressure is lower than a predetermined threshold supply pressure, and directing a control signal from the fluid information unit to the one or more demand control units to reduce demand for the fluid. In addition, a method and apparatus are described for measuring density of a fluid flowing through a demand pipe. The method includes determining that fluid flow through the demand pipe is stable, measuring fluid flow rate through the demand pipe, preventing the fluid from flowing into the demand pipe for a sample period of time, measuring a drop in fluid pressure in the demand pipe during the sample period, and determining the density from the measured pressure drop. Also, a utility meter for metering a fluid flowing through a supply pipe and a demand pipe having an audible indicator to provide an audible signal to a user is described.

Abstract: A method and apparatus are described for controlling demand of a fluid. The method includes measuring a fluid supply pressure in a supply pipe, determining that the fluid supply pressure is lower than a predetermined threshold supply pressure, and directing a control signal from the fluid information unit to the one or more demand control units to reduce demand for the fluid. In addition, a method and apparatus are described for measuring density of a fluid flowing through a demand pipe. The method includes determining that fluid flow through the demand pipe is stable, measuring fluid flow rate through the demand pipe, preventing the fluid from flowing into the demand pipe for a sample period of time, measuring a drop in fluid pressure in the demand pipe during the sample period, and determining the density from the measured pressure drop. Also, a utility meter for metering a fluid flowing through a supply pipe and a demand pipe having an audible indicator to provide an audible signal to a user is described.

Abstract: A method and apparatus are described for controlling demand of a fluid. The method includes measuring a fluid supply pressure in a supply pipe, determining that the fluid supply pressure is lower than a predetermined threshold supply pressure, and directing a control signal from the fluid information unit to the one or more demand control units to reduce demand for the fluid. In addition, a method and apparatus are described for measuring density of a fluid flowing through a demand pipe. The method includes determining that fluid flow through the demand pipe is stable, measuring fluid flow rate through the demand pipe, preventing the fluid from flowing into the demand pipe for a sample period of time, measuring a drop in fluid pressure in the demand pipe during the sample period, and determining the density from the measured pressure drop. Also, a utility meter for metering a fluid flowing through a supply pipe and a demand pipe having an audible indicator to provide an audible signal to a user is described.

Abstract: An absolute linear encoder includes an index channel and at least two counter channels. The spacing between markings on the index channel is constant, and the spacing between markings on the first and second channels is predetermined so that the positions of the markings in the first and second channels vary so as to provide a unique signature for each position along the encoder. The linear encoder includes quadrature channels to provide increased resolution and to determine the direction of translation. The encoder is provided with a detector unit to detect positions of the markings in each channel, and a processing unit to calculate an absolute position from the detected marking positions. A method of producing the absolute linear encoder includes selecting spacings for markers in the quadrature, index, first and second channels in order to provide a desired resolution and encoder length.

Abstract: An apparatus and method for metering fluid flow is disclosed. A fluid dispensing unit is coupled between a supply pipe and a demand pipe, and dispenses fluid received from the supply pipe to the demand pipe. The demand pipe is coupled to one or more fluid-expending appliances. The pressure of the fluid in the demand pipe is monitored by a fluid information unit. The fluid information unit and fluid dispensing unit cooperate to maintain the fluid flowing through the demand pipe at a substantially constant demand fluid pressure by monitoring fluid flowing through the demand pipe and actively dispensing fluid received from the supply pipe into the demand pipe to maintain the demand fluid pressure at a pre-established demand pressure level. The fluid information unit and fluid dispensing unit also cooperate to meter or measure the volume of fluid dispensed through the fluid dispensing unit.