Provided is a thermal flow meter to improve the measurement accuracy of a temperature detector provided in a thermal flow meter. The thermal flow meter includes a bypass passage through which a measurement target gas 30 flowing through a main passage flows, and a circuit package 400 which includes a measurement circuit for measuring a flow rate of the measurement target gas 30 flowing through the bypass passage and a temperature detecting portion 452 for detecting a temperature of the measurement target gas. The circuit package 400 includes a circuit package body which is molded by a resin to internally envelope the measurement circuit and a protrusion 424 molded by the resin. The temperature detecting portion 452 is provided in the leading end portion of the protrusion 424, and at least the leading end portion of the protrusion protrudes to the outside from a housing 302.

Provided is a thermal flow meter that can be prevented from being eroded due to adhesion of water or like to a cut end portion of the lead exposed from the mold resin of the circuit package. A thermal flow meter 300 of the present invention is a thermal flow meter having a circuit package 400 formed by mounting a detection element 518 on leads 544 and 545 supported by a support frame 512, sealing with a mold resin, and cutting off the support frame 512, wherein cut end portions 544a and 545a of the leads 544 and 545 exposed from the mold resin of the circuit package 400 by cutting off the support frame 512 is covered by a covering portion 371.

An electronic utility gas meter using MEMS thermal mass flow sensor to meter gas custody transfer and MEMS gas thermal property sensor to compensate the metering values due to gas composition variations is disclosed in the present invention. The meter is designed to have a MEMS mass flow sensor to meter the city utility gas consumption independent of environmental temperature and pressure while a MEMS gas thermal property or dual gas thermal property sensors to compensate the tariff due to the gas composition variations for compliance with the current regulation requirements of tariff and remove the major concerns for the wide deployment of the thermal mass MEMS utility gas meters.

A system for measuring gas flow generally including a passive acoustic wave generator disposed in a gas flow stream to passively generate an audio signal through vortex shedding, a sound capturing instrument disposed outside the gas stream to produce an electrical signal representative of the acoustic signal, a temperature sensor to obtain temperature measurements indicative of the temperature of the gas flow stream and a control system for determining the gas flow, such as velocity or flow rate, as a function of the acquired acoustic and temperature measurements. The acoustic wave generator includes a corrugated flow channel whose geometric design is so tuned to generate an acoustic emission whose frequency signature varies as a function of the gas flow velocity. The control system may acquires time-domain acoustic data, and process that data to obtain a frequency-domain representation from which gas velocity or gas flow rate can be determined.

Techniques detect a low gas-pressure condition within a region without the use of pressure sensors. In an example, gas usage at a service site is disaggregated to show use by individual appliances. A flowrate of gas at an appliance (e.g., a gas hot water tank) having a generally fixed-rate of gas-consumption is determined. Based at least in part on the flowrate of gas at the appliance, and an historical gas flowrate at that appliance, it is determined if gas pressure at the service site is lower than expected. In an example, failure of the appliance to use its typical fixed-flowrate may indicate low gas pressure at the service site. Information is obtained from a second gas meter at a second service site. Based on the gas pressure at the first and second service sites being lower than expected, a low gas pressure situation may exist in a regional area.

An electronic utility gas meter using MEMS thermal mass flow sensor to meter gas custody transfer and MEMS gas thermal property sensor to compensate the metering values due to gas composition variations is disclosed in the present invention. The meter is designed to have a MEMS mass flow sensor to meter the city utility gas consumption independent of environmental temperature and pressure while a MEMS gas thermal property or dual gas thermal property sensors to compensate the tariff due to the gas composition variations for compliance with the current regulation requirements of tariff and remove the major concerns for the wide deployment of the thermal mass MEMS utility gas meters.

A multi-chamber rate-of-change flow meter system and methods for operating the same are disclosed. The multi-chamber rate-of-change flow meter system includes a collection of N chambers, means for drawing a gas into or out of the collection of N chambers, N pressure sensors corresponding one of the N chambers, and means for redistributing the gas among the chambers. A measurement module is coupled to the pressure sensors to obtain a rate of change of pressure in each of the chambers due to the redistribution of the gas and calculate a flow rate of the gas flowing into or out of the collection of N chambers based upon the rate of change of pressure in each of the chambers.

A fuel gauging system for a fuel tank containing fuel and an ullage gas in an ullage of the tank. The fuel gauging system pressurizes/depressurizes the ullage gas and measures changes in conditions of the ullage gas to determine ullage gas volume and thus volume of the fuel. The system may infer one or more values in the volume calculation to reduce the number of measurements involved. The inferred values may come from known operating characteristics of an inerting system integrated with the fuel gauging system. The system may use a control valve that operates within the limits of a climb-dive valve to generate the system response. The control valve may control delivering or receiving ullage gas from another tank to preserve the ullage gas. An inerting system may be integrated into such a paired-tank fuel gauging system.

A device for measuring the speed or flow of a gas at a temperature different from an ambient temperature is provided, which includes: a first platform suspended by first arms above a support designed to be kept at an ambient temperature, the first arms comprising thermoelectric strips designed to supply a first voltage based on the difference between the temperatures of the first platform and the support; and a processing unit designed to supply the speed or flow measurement on the basis of the first voltage, the gas temperature and the ambient temperature.

An electronic utility gas meter using MEMS thermal time-of-flight flow sensor to meter gas custody transfer mass flowrate and an additional MEMS gas sensor to measure the combustion gas composition for the correlations to the acquisition of gas high heat value simultaneously is disclosed in the present invention. The meter is designed for the applications in the city utility gas consumption in compliance with the current tariff while metering the true thermal value of the delivered gases for future upgrades. Data safety, remote data communication, and other features with state-of-the-art electronics are also included in the design.