Book contents
- Front Matter
- Contents
- Preface
- Acknowledgments
- Nomenclature
- Chapter 1 Introduction
- Chapter 2 Fluid Mechanics Essentials
- Chapter 3 Specification, Selection, and Audit
- Chapter 4 Calibration
- Chapter 5 Orifice Plate Meters
- Chapter 6 Venturi Meter and Standard Nozzles
- Chapter 7 Critical Flow Venturi Nozzle
- Chapter 8 Other Momentum-Sensing Meters
- Chapter 9 Positive Displacement Flowmeters
- Chapter 10 Turbine and Related Flowmeters
- Chapter 11 Vortex-Shedding, Swirl, and Fluidic Flowmeters
- Chapter 12 Electromagnetic Flowmeters
- Chapter 13 Ultrasonic Flowmeters
- Chapter 14 Mass Flow Measurement Using Multiple Sensors for Single- and Multiphase Flows
- Chapter 15 Thermal Flowmeters
- Chapter 16 Angular Momentum Devices
- Chapter 17 Coriolis Flowmeters
- Chapter 18 Probes for Local Velocity Measurement in Liquids and Gases
- Chapter 19 Modern Control Systems
- Chapter 20 Some Reflections on Flowmeter Manufacture, Production, and Markets
- Chapter 21 Future Developments
- Bibliography
- A Selection of International Standards
- Conferences
- References
- Index
Chapter 4 - Calibration
Published online by Cambridge University Press: 22 September 2009
- Front Matter
- Contents
- Preface
- Acknowledgments
- Nomenclature
- Chapter 1 Introduction
- Chapter 2 Fluid Mechanics Essentials
- Chapter 3 Specification, Selection, and Audit
- Chapter 4 Calibration
- Chapter 5 Orifice Plate Meters
- Chapter 6 Venturi Meter and Standard Nozzles
- Chapter 7 Critical Flow Venturi Nozzle
- Chapter 8 Other Momentum-Sensing Meters
- Chapter 9 Positive Displacement Flowmeters
- Chapter 10 Turbine and Related Flowmeters
- Chapter 11 Vortex-Shedding, Swirl, and Fluidic Flowmeters
- Chapter 12 Electromagnetic Flowmeters
- Chapter 13 Ultrasonic Flowmeters
- Chapter 14 Mass Flow Measurement Using Multiple Sensors for Single- and Multiphase Flows
- Chapter 15 Thermal Flowmeters
- Chapter 16 Angular Momentum Devices
- Chapter 17 Coriolis Flowmeters
- Chapter 18 Probes for Local Velocity Measurement in Liquids and Gases
- Chapter 19 Modern Control Systems
- Chapter 20 Some Reflections on Flowmeter Manufacture, Production, and Markets
- Chapter 21 Future Developments
- Bibliography
- A Selection of International Standards
- Conferences
- References
- Index
Summary
INTRODUCTION
The object of calibration is to benchmark a flowmeter to an absolute datum. Just as a benchmark tells us how a particular geographical point compares in height with sea level datum, so a calibration of a flowmeter tells us how the signal from the flowmeter compares with the absolute standard of a national laboratory. The analogy is not perfect at this stage. The national laboratory standard must also be compared with other more fundamental measures of time and mass, and it will be essential to check and compare different national standards in different countries from time to time.
There is a desire to reference back to fundamental measurements such as mass, length, and time. Thus if we can measure mass flow on a calibration facility by using fundamental measurements of mass and time, this will bring us nearer to the absolute values than, say, obtaining the volume of a calibration vessel by using weighed volumes of water and deducing the volume from the density. The first is more correctly termed primary calibration, whereas the second fails strictly to achieve this. It is likely that the final accuracy will reflect this. Liquid calibration facilities can achieve a rather higher accuracy than is possible for most of the gas calibration facilities. In part, this difference will result from the lower density and the increased difficulties of handling a gas.
- Type
- Chapter
- Information
- Flow Measurement HandbookIndustrial Designs, Operating Principles, Performance, and Applications, pp. 61 - 94Publisher: Cambridge University PressPrint publication year: 2000