A gas supply system capable of flow measurement includes a flow controller that controls the flow rate of a flowing gas, a first shutoff valve provided downstream of the flow controller, a second shutoff valve provided in a first flow passage communicating with the downstream side of the first shutoff valve, a second flow passage that branches from the first flow passage, a third shutoff valve provided in the second flow passage, a pressure sensing device that detects a pressure in a flow passage controlled by the first, second, and third shutoff valves, a temperature sensing device that detects a temperature in the flow passage controlled by the first, second, and third shutoff valves, a volume measuring tank connected downstream of the third shutoff valve and having a known volume, and an arithmetic and control unit that obtains a passage volume controlled by the first, second, and third shutoff valves by applying Boyle's law to open and closed states of the third shutoff valve and calculates the flow rate of the flow controller, using the passage volume and detection values obtained by the pressure sensing device and the temperature sensing device.

A side view fluid meter counter assembly comprises a mounting bracket to mount a mechanical counter to an end of a fluid meter (e.g. gas meter) and a drive mechanism to drive a counter shaft of the mechanical counter from rotational movement of a rotationally driven member of the fluid meter. The rotationally driven member has a drive shaft extending in an end facing direction to connect to the drive mechanism and the mounting bracket mounts the mechanical counter in an orthogonal direction to the end facing direction such that a face of the mechanical counter is viewable from a side of the meter. The drive mechanism may comprise a worm drive. The drive mechanism may further comprise a pair of bevel gears. The mounting bracket further mounts the drive mechanism. Further provided is a fluid meter having a side view counter.

Techniques for the design and operation of an efficient battery-powered meter are described herein. A metrology unit of the meter may be at least partially located in the gas flow of a pipe, and measures gas flow rate data according to a static flow sensor. The metrology unit calculates raw gas-volume data using at least the flow rate data as input. The metrology unit measures gas temperature to produce gas temperature data, and adjusts the raw gas-volume data, based at least in part on the gas temperature data, to produce corrected gas-volume data. The metrology unit accumulates the corrected gas-volume data over multiple minutes, hours or even days, and then sends the accumulated corrected gas-volume data to an index unit of the meter. By accumulating the data over time, fewer data transmissions are required. The index unit may send the accumulated the accumulated corrected gas-volume data to a utility server.

In an apparatus and method for measuring air flow in a duct, e.g. in a ventilation duct, the apparatus includes a sensor fittable into connection with the duct at a certain distance from an interference source, the sensor including an ultrasound transmitter and at least two ultrasound receivers, and a control unit to which the ultrasound transmitter and ultrasound receivers are connectable. The control unit is adapted to measure the phase difference of the ultrasound signal received at the same moment in time by at least two ultrasound receivers fitted into connection with the duct and, based on the measured phase difference, to determine the flow velocity and/or flow direction of the air. The control unit is adapted to compensate the determined flow velocity and/or flow direction of the air with a coefficient that is formed on the basis of the diameter of the duct, the type of interference source and the distance between the sensor and the interference source.

A mass flow control system can be self verified for its accuracy when controlling a flow to a process. The system comprises: a control valve for controlling the flow of fluid through the system as a function of a control signal; a controller for generating the control signal as a function of measured flow of fluid through the system and a targeted flow set point; a pressure sensor for measuring the controlling fluid pressure for use in measuring and verifying the flow rate; and a source of fluid for providing a known volume of fluid for use in verifying the system accuracy anytime between steps of the flow control process.

An apparatus for calculating a thermal conductivity of a gaseous substance is provided. The apparatus includes a substrate; a cover member disposed on the substrate, wherein the cover member comprises a flow tunnel for the gaseous substance; a flow sensing element disposed on the substrate, wherein the flow sensing element is exposed to the gaseous substance in the flow tunnel; and a pressure sensing element disposed on the substrate, wherein the pressure sensing element is exposed to the gaseous substance in the flow tunnel.

In order to accurately calculate an estimated flow rate by a dynamic constant volume method, a flow rate calculation system including a tank into which fluid flows, an inflow line through which the fluid flows into the tank, and a pressure sensor that detects the pressure inside the tank is adapted to include: a pressure change data storage part that stores pressure change data indicating a temporal change in the pressure detected by the pressure sensor during an inflow period; a flow rate calculation part that calculates the estimated flow rate during the inflow period based on a pressure change rate; and a flow rate correction part that, on the basis of first pressure detected by the pressure sensor after a predetermined time has elapsed after the inflow period and second pressure included in the pressure change data and higher than the first pressure, corrects the estimated flow rate.

To obtain a low-pressure-loss physical quantity detection device that can detect a plurality of physical quantities of intake air. A physical quantity detection device of the present invention that detects a plurality of physical quantities of a measured gas flowing in a main passage, the physical quantity detection device includes: a circuit board on which a sensor that detects the plurality of physical quantities and an electronic component that controls the physical quantities are mountable; a circuit board accommodating unit that accommodates the circuit board; and a sub-passage in which a flow sensor is disposed. The circuit board is accommodated in the circuit board accommodating unit on an upstream side of the sub-passage, and disposed in parallel with the measured gas flowing through the main passage.

Techniques for the design and operation of an efficient battery-powered meter are described herein. A metrology unit of the meter may be at least partially located in the gas flow of a pipe, and measures gas flow rate data according to a static flow sensor. The metrology unit calculates raw gas-volume data using at least the flow rate data as input. The metrology unit measures gas temperature to produce gas temperature data, and adjusts the raw gas-volume data, based at least in part on the gas temperature data, to produce corrected gas-volume data. The metrology unit accumulates the corrected gas-volume data over multiple minutes, hours or even days, and then sends the accumulated corrected gas-volume data to an index unit of the meter. By accumulating the data over time, fewer data transmissions are required. The index unit may send the accumulated the accumulated corrected gas-volume data to a utility server.

A diagnostics system comprising a controller for controlling operations of a mass flow controller. The controller is communicable coupled to at least one sensor and to a valve and tuned to control the valve based on a predetermined set point value and communication from the at least one sensor. The controller determines at least one predetermined value associated with a reverse flow of a fluid and either cause the controller to enter a hard fault or a safe state. The predetermined value of the flow is either a percentage of total flow or a percentage of total flow over a time period. The controller can log the date, time, and a device identifier in response to determining the at least one predetermined value. In addition, the diagnostics system can include a centralized controller configured to receive diagnostics data from a plurality of controllers and control operation of the controllers.