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.

A flow meter for measuring a flow rate of a fluid may include a cartridge containing certain components such as a flow sensor. The cartridge is removable from the flow meter such that it may be replaced with a new cartridge, allowing calibration of the flow meter while enabling the flow meter to continue to be operated with another cartridge in the place of the removed cartridge. The flow meter may be configured to direct fluid flow away from selected components of the flow meter.

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.

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.

A flow meter for measuring a flow rate of a fluid may include a cartridge containing certain components such as a flow sensor. The cartridge is removable from the flow meter such that it may be replaced with a new cartridge, allowing calibration of the flow meter while enabling the flow meter to continue to be operated with another cartridge in the place of the removed cartridge. The flow meter may be configured to direct fluid flow away from selected components of the flow meter.

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.

Apparatus for determining a measurement error of a displacement volumetric meter, the meter having bellows which in use expand and contract to transmit a fluid. The apparatus including a transducer operable to detect movement of the bellows and to generate a signal which varies in accordance with the movement of the bellows; and a computing device in communication with the transducer so as to receive the signal therefrom, the computing device being operable to determine a flow rate of fluid through the meter based on the signal, and to determine a measurement error of the meter based on the determined flow rate. A corresponding method, meter monitoring device and meter measurement error determining device are also disclosed.

The mass of a fluid flowing through a flow rate meter at a temperature which fluctuates in a given temperature range is determined by driving an exciter magnet system through the fluid with an exact correlation between the fluid volume flowing there through and the movement path covered by the exciter magnet system, producing a measurement voltage pulse after each passage through a movement path corresponding to a unit volume of the fluid by means of a Wiegand wire and a coil surrounding same, at each measurement time charging a first energy storage means by electric energy contained in each measurement voltage pulse, and using same as operating energy for measurement of the instantaneous temperature of the fluid, producing a temperature value as an integral multiple of the smallest temperature measurement unit to be resolved and an integral count value including said temperature value, and adding same to a sum contained in a non-volatile storage means from the precedingly ascertained count values for forming an ongoing sum in the non-volatile storage means and passing same to a processor which can be supplied with external energy and which calculates therefrom the temperature-corrected delivery volume of the fluid.