A Flow Measurement Orientation
  The Flow Pioneers
  Flow Sensor Selection
  Accuracy vs. Repeatability


Differential Pressure Flowmeters
  Primary Element Options
  Pitot Tubes
  Variable Area Flowmeters


Mechanical Flowmeters
  Positive Displacement   Flowmeters
  Turbine Flowmeters
  Other Rotary Flowmeters

Electronic Flowmeters
  Magnetic Flowmeters
  Vortex Flowmeters
  Ultrasonic Flowmeters


Mass Flowmeters
  Coriolis Mass Flowmeters
  Thermal Mass Flowmeters
  Hot-Wire Anemometers


A Level Measurement Orientation
  Level Sensor Selection
  Boiling & Cryogenic Fluids
  Sludge, Foam, & Molten   Metals


Pressure/Density Level Instrumentation
  Dry & Wet Leg Designs
  Bubbler Tubes
  Floats & Displacers


RF/Capacitance Level Instrumentation
  Theory of Operation
  Probe Designs
  Installation Considerations


Radiation-Based Level Instrumentation
  Radar & Microwave
  Ultrasonic Level Gages
  Nuclear Level Gages


Specialty Level Switches
  Thermal Switches
  Vibrating Switches
  Optical Switches


REFERENCE SECTIONS
  Editorial
  About OMEGA
  Information Resources
  Glossary

  Two Sides, Same Coin

Of all types of process measurements, none are more closely linked, more nearly complementary, than flow and level. Together, flowmeters and level gauges answer the fundamental question of "How much?" in industrial and laboratory processes worldwide. Together, they determine how much raw material (or finished inventory) you've got on hand--and how fast you're using it up (or producing it). Together, they provide the right and left hands of process accountability, the checks and balances needed to verify and reconcile efficient manufacturing processes and sound research methodologies.

Flow and level also share the distinction of being among the most difficult of primary process measurements to make with accuracy. Hence, an amazingly wide variety of niche instrumentation technologies based on different physical principles of fluids have been developed over the years to fit specific application requirements.

To help make sense of the legion of options available and how they can best be made to work together in your processes, this fourth volume in OMEGA's Transactions in Measurement & Control series explores the pros and cons of some 30 different flow measurement technologies and approximately 20 different level technologies.

From operating principles to selection criteria to installation guidelines, we believe you'll find this volume a useful primer--whether you've spec'ed out a thousand systems or are working on your first. As always, feel free to call OMEGA any time you think we can be of help. Our staff of experienced application engineers is ready and waiting.

Meanwhile, we hope you find this issue of Transactions useful and that it finds a permanent home on your reference shelf. If the first three issues on "Non-Contact Temperature Measurement," "Data Acquisition," and "Force-Related Measurements" somehow missed you, visit us on the web at www.omega.com to order your complimentary copies. P.S. If you wish to submit an article of relevance for future issues of Transactions, please submit to my attention via mail (P.O. Box 4047, Stamford, CT 06907), FAX (203-359-7700), or e-mail (info@omega.com).