A flow rate diagnosis apparatus includes: a main line in which a tank having a volume is provided; a branch line that branches from the main line on an upstream side of the tank; a first open close valve provided in the branch line; a second open close valve provided in the main line; a dead volume defined from the diagnosis object as an upstream end and the first open close valve and the second open close valve as downstream ends; and a second pressure control mechanism that controls a fluid flowing through the main line such that the pressure of the fluid in the dead volume is maintained at a second setting pressure during an inflow mode during which the fluid is caused to flow into the tank by closing of the first open close valve and opening of the second open close valve after a preparation mode.

In one aspect, data characterizing a fuel storage facility can be received from a sensor in operable communication with the fuel storage facility. An estimate of meter drift of a flow meter of a fuel dispenser in fluid communication with the fuel storage facility can be determined based on the received data. The estimate of meter drift can be determined based on at least one predictive model that predicts whether a calibration parameter characterizing a calibration of the flow meter has deviated from a predetermined flow meter calibration parameter. The estimate of meter drift can be provided.

Mass flow verification systems and apparatus may verify mass flow rates of mass flow controllers (MFCs) based on choked flow principles. These systems and apparatus may include a plurality of differently-sized flow restrictors coupled in parallel. A wide range of flow rates may be verified via selection of a flow path through one of the flow restrictors based on an MFC's set point. Mass flow rates may be determined via pressure and temperature measurements upstream of the flow restrictors under choked flow conditions. Methods of verifying a mass flow rate based on choked flow principles are also provided, as are other aspects.

An HVAC system and method for characterizing a chosen VAV valve involves measuring the valve's volumetric flow rate versus valve position at just one or at some other limited number of data points and comparing that to the average characteristics a rather large group of similar valves. A custom characterization of airflow versus valve position for the chosen VAV valve is then created based on a difference between the characteristics of the chosen valve and that of the group of valves. In some examples, the VAV valve is of a venturi style such that a generic characterization of the group of valves is substantially linear when their flow rates are expressed logarithmically.

A new DP meter diagnostic system for wet gas flow builds on existing diagnostic techniques. Based on new diagnostic parameters and calculations derived from them, blocked pressure ports or impulse lines can be identified or wet gas established as the cause of an abnormal reading. Further diagnostic techniques can take advantage of the new diagnostic parameters to predict a liquid loading parameter, gas flow rate and fluid flow rate for wet gas flow.

A diagnostics system, for mass flow controller calibration, comprising a controller communicable coupled to a sensor(s) and a valve. The controller controls the valve based on a predetermined set point value and communication from the at least one sensor. The controller determines a number of set point value adjustments and compares results of a calibration operation and a set point value plus a tolerance value. The controller generates a notification message indicating at least one of the predetermined number of set point value adjustments and results of the comparing. The controller calibrates the mass flow controller based on, at least in part, one of a predetermined number of set point value adjustments, results of the comparison, and user input. The notification message can comprise temperature values, valve drive values, sensor flow rate values, gas flow hours, and a remaining number of set point adjustments based on a total fluid hours.

A respiratory flow therapy apparatus including a sensor module can measure a flow rate of gases or gases concentration provided to a patient. The sensor module can be located after a blower and/or mixer. The sensor module can include at least an ultrasonic transmitter, a receiver, a temperature sensor, a pressure sensor, a humidity sensor and/or a flow rate sensor. The receivers can be immersed in the gases flow path. The receivers can cancel delays in the transmitters and improve accuracy of measurements of characteristics of the gases flow. The receivers can allow for detection of a fault condition in a blower motor of the apparatus.

In order to provide a fluid device that makes it possible for operation command signals other than existing operation command signals to be received without a software modification having to be implemented in an already constructed system, in a fluid device that measures or controls physical quantities of a fluid, there are provided a command signal receiving unit that receives a predetermined plurality of types of operation command signals, and also command signal modes, which are values thereof or time series variations of the values thereof, and a command signal recognition unit that, when the command signal mode of a predetermined operation command signal received by the command signal receiving unit falls outside predetermined conditions that have been set in advance, recognizes the predetermined operation command signal that contains the command signal mode as being a different type of operation command signal.

A U-shaped tube is used to measure the mass flow rate of the fluid using both thermal method and the Coriolis principle simultaneously. Two resistant coils are wound on the tube to do the thermal measurement and an excitation coil and two optical sensors are used to do the Coriolis flow measurement. It takes the advantages of both technologies and create a flow sensor which is super accurate, gas type insensitive, long-term stable and fast responsive without too much pressure drop.

A valve fully closing part; a calibrating volume calculation part that calculates a calibrating volume on the basis value of an integration of a flow rate measured value outputted from a flow rate sensor in a fluid parameter changing interval; and a calibration part that calibrates a flow rate on the basis of the calculated calibrating volume and a preset reference volume are provided.