The sequential volumetric flowmeter includes a static measurement enclosure which is connected to a fluid inlet duct and a fluid outlet duct and in which a movable separator can move to form a variable input volume and a variable output volume, a mobile return spring tending to reduce the variable input volume, the minimum volume of which is fixed by a start-of-stroke static stop and a movable start-of-stroke stop; a bypass valve controlled by a valve actuator can put the variable input volume in communication with the variable output volume, and a displacement measurement unit informing a computer about the position of the movable separator.

Devices, methods, and systems for operating gas meters are described herein. The systems may include a gas measuring system connectable to a gas line, where the gas measuring system may include a flow rate sensor, a pressure sensor, and a controller in communication with the flow rate sensor and the pressure sensor. The flow rate sensor and the pressure sensor may be configured to sense measures of a gas passing through the gas line. The controller may repeatedly obtain pressure measurements at set pressure measurement times. Measures from the flow sensor may be monitored and when a measure from the flow sensor measure meets a flow rate criteria, the controller may trigger an extra pressure measurement without waiting for a next pressure measurement time. The controller may initiate closing of a gas valve when a measure from the pressure sensor exceeds a threshold value.

Devices, methods, and systems for operating gas meters are described herein. The systems may include a gas measuring system connectable to a gas line, where the gas measuring system may include a flow rate sensor, a pressure sensor, and a controller in communication with the flow rate sensor and the pressure sensor. The flow rate sensor and the pressure sensor may be configured to sense measures of a gas passing through the gas line. The controller may repeatedly obtain pressure measurements at set pressure measurement times. Measures from the flow sensor may be monitored and when a measure from the flow sensor measure meets a flow rate criteria, the controller may trigger an extra pressure measurement without waiting for a next pressure measurement time. The controller may initiate closing of a gas valve when a measure from the pressure sensor exceeds a threshold value.

A flow rate measurement device includes a flow rate measurer to measure a fluid flow rate at regular time intervals, a period setting unit, an arithmetic unit to calculate first average flow rates and amounts of change each between the average flow rates in sequence, and second average flow rates and amounts of change each between the average flow rates in sequence, and a fuel cell determinator to determine whether a fuel cell is in operation. The fuel cell determinator determines that a fuel cell is in operation when an increment of the second average flow rate repeats for first predetermined successive times, an increment of the first average flow rate repeats for second predetermined times or more in each of the second periods, and an increment of the first average flow rate not greater than or equal to a third predetermined flow rate in each of the second periods.

A differential monitoring system of carbon dioxide levels within an associated building with a monitoring zone including a quantity of captured carbon dioxide and a reference zone that is spaced away from the monitoring zone. The differential monitoring system includes a first carbon dioxide monitoring inlet disposed within the monitoring zone. A second carbon dioxide monitoring inlet is disposed within the monitoring zone in spaced relation to the first carbon dioxide monitoring inlet and/or is disposed within the reference zone in spaced relation to the first carbon dioxide monitoring zone. A controller is operable to determine when a carbon dioxide level at the second carbon dioxide monitoring inlet exceeds a carbon dioxide level at the first carbon dioxide monitoring inlet by a predetermined differential threshold. The inlets can be part of an aspirated sampling system and/or part of a distributed sensor system. Methods of monitoring carbon dioxide levels are also included.

A flow meter is disclosed. The flow meter can include a housing that has a cavity. The flow meter can also include a deformable tube that is disposed in the cavity. The deformable tube can comprise a portion of a flow path of a fluid substance. The flow meter can further include a cam that is rotatably coupled to the housing. A portion of the cam is configured to press against a portion of the collapsible tube so as to deform the portion of the collapsible tube. The cam can be configured to rotate in response to a flow of the fluid substance in the flow path.

Devices, methods, and systems for operating gas meters are described herein. The systems may include a gas measuring system connectable to a gas line, where the gas measuring system may include a flow rate sensor, a pressure sensor, and a controller in communication with the flow rate sensor and the pressure sensor. The flow rate sensor and the pressure sensor may be configured to sense measures of a gas passing through the gas line. The controller may repeatedly obtain pressure measurements at set pressure measurement times. Measures from the flow sensor may be monitored and when a measure from the flow sensor measure meets a flow rate criteria, the controller may trigger an extra pressure measurement without waiting for a next pressure measurement time. The controller may initiate closing of a gas valve when a measure from the pressure sensor exceeds a threshold value.

Devices, methods, and systems for operating gas meters are described herein. The systems may include a gas measuring system connectable to a gas line, where the gas measuring system may include a flow rate sensor, a pressure sensor, and a controller in communication with the flow rate sensor and the pressure sensor. The flow rate sensor and the pressure sensor may be configured to sense measures of a gas passing through the gas line. The controller may repeatedly obtain pressure measurements at set pressure measurement times. Measures from the flow sensor may be monitored and when a measure from the flow sensor measure meets a flow rate criteria, the controller may trigger an extra pressure measurement without waiting for a next pressure measurement time. The controller may initiate closing of a gas valve when a measure from the pressure sensor exceeds a threshold value.

Gas meter includes shutoff valve, return unit, flow rate measurer, display, communication unit that communicates with an outside, controller, area information setting unit, and area information comparator. The gas meter compares, by area information comparator, a preset area information held in area information setting unit with a specified value of area information added to a remote shutoff instruction received by communication unit, and when the preset area information and the specified value of the added area information match, shutoff valve is closed.

A method of measuring airflow from an HVAC outlet vent using a volume fill airflow measurement device having a LIDAR or Time-of-Flight (ToF) laser-ranging sensor to detect a filled state of a volume capture element or bag, comprising placing a frame having the bag sealably attached thereto over the vent to be measured, starting a timer, stopping the timer automatically in response to the LIDAR or Time-of-Flight (ToF) laser-ranging sensor measuring the distance to be within a predetermined range, and calculating the measured airflow based on the volume of the bag and the time for the airflow to fill the bag. The measured airflow is then displayed on the device display.