Showing papers on "Thermal mass flow meter published in 1974"

Flow and time proportional sampling system

Abstract: A sampling system for drawing samples from a fluid flow which is responsive to manual actuation, predetermined increments of flow volume, or predetermined increments of time. The system includes a flow meter and a flow sampler interconnected and physically located in the vicinity of the flow being monitored. The flow meter converts the flow head to flow rate and subsequently to flow volume. The head to flow conversion is mechanical and provides for flow measurement through a flow channel having a given cross section shape over a wide range of shape sizes by means of an electrical adjustment. The flow meter provides for flow measurement through flow channels having varying cross secton shapes by means of selectively engaging a predetermined one of a plurality of cams designed to convert head to flow is being measured. The sampler is electrically connected to the flow meter for use in the sample per flow volume mode and provides for a constant volume sample which is independent of flow head, sampler height above the flow surface, power source voltage level, pumping time or any of the other variables which heretofore affected the sample volume. Automatic sequencing within the sampler provides for purging the system, drawing the sample from the flow, sizing the sample, depositing the sample in a storage container, and purging the sampler intake after storage. Means are provided for depositing a predetermined number of samples in each of a plurality of storage containers, or for utilizing a predetermined number of containers for holding each sample, and for de-energizing the sampler until manually attended after a predetermined number of storage containers have received samples. The automatic internal sampler sequencing is initiated by an input signal which is generated by either a flow or time proportional sensor or manual actuation according to control selection.

Improved fluid flow sensor configuration

Abstract: An improved fluid flow sensor configuration comprises a thin membrane of a low thermally conductive material having one surface in thermal contact with the heating and temperature sensitive elements of a fluid flow sensor and the other surface in thermal contact with a fluid whose flow rate is measured by the fluid flow sensor.

Fluid flow meter with counter rotating turbine impellers

Abstract: A fluid flow meter with two independantly counter rotating turbine impellers is disclosed in which fluid characteristics and/or upstream flow disturbances cause minimal variations in volume flow rate measurements by the meter as a result of fluidynamic interaction between the impellers The angular velocities of each of the impellers are sensed in a conventional manner after which the velocity signals are added to indicate a total volume thruput, and/or rate of flow, and optionally compared to indicate an occurance of mechanical or electronic degradation

Apparatus and method for measuring fluid flow over a wide range of fluid flow conditions and viscosities

Abstract: Flowmeter apparatus and method for obtaining accurate measurement of fluid flow, not only in the turbulent flow range, but also in the laminar and transitional flow ranges by compensation of the meter reading. The meter reading is also compensated for change in viscosity of the fluid flowing through the meter. The compensation for flow range is based on the best-fit straight line approach obtained by matching straight line segments to the quantity versus frequency output curve throughout the laminar and transitional ranges, and compensating the flowmeter reading in accordance with the shape of the straight line segments. The compensation for change in kinematic viscosity of the fluid is added to the flowmeter output in accordance with the temperature-viscosity relationship for the fluid and in accordance with a ratio of compensation factors between the actual fluid and a reference fluid.

ASRDI oxygen technology survey. Volume 6: Flow measurement instrumentation

Abstract: A summary is provided of information available on liquid and gaseous oxygen flowmetering including an evaluation of commercial meters. The instrument types, physical principles of measurement, and performance characteristics are described. Problems concerning flow measurements of less than plus or minus two percent uncertainty are reviewed. Recommendations concerning work on flow reference systems, the use of surrogate fluids, and standard tests for oxygen flow measurements are also presented.

Neutronic flow meter

Abstract: A neutronic flow meter which uses a neutron source surrounded by a moderator at cryogenic temperatures and neutron detectors located upstream and downstream of the source to measure the fluid flow rate through a pipe and alternately a ships speed.