CME gas flowmeters priniiples

PRINCIPLES OF OPERATION

The flow of the test gas through the linear restrictor(s) creates a pressure difference (differential pressure) between the upstream and the downstream pressure taps shown in the cut-away drawing. The differential pressure is directly related to the flow and viscosity of the gas, according to the 140-year old Hagen-Poiseuille law.

The flow inside the element is laminar (not turbulent) so that as flow rate is decreased the Reynolds Number is decreased and the flow is even more laminar. All of the flowmeters, flow systems and flow calibrators made by CME utilize these Laminar Flow Elements (LFE’s).

CME Laminar Flow Elements and Systems provide the following general advantages:
• NIST Traceable
• High Accuracy
• Low Pressure Drops
• Multiple Gas Applicability
• No Moving Parts to Wear Out
• LFE is 304/316 Stainless Steel

SMART FLOWMETERS, SYSTEMS AND CALIBRATORS
“Throw Your Calculator Away”
CME strongly advocates the use of SMART flowmeters, systems and calibrators to meet the increasing demand for greater accuracy of measurement in test and calibration. CME SMART flowmeters provide both volumetric (actual) and standard/mass flow measurements.

To maintain the accuracy of the Laminar Flow Element’s calibration, it is necessary to measure the temperature and pressure of the gas flow stream. CME SMART flowmeters have all components calibrated together, as a system, and dedicated flow computers automatically make all flow calculations. This eliminates the need for manual calculations and additional operator training.

CME SMART flowmeters have all components of the measurement calibrated together and dedicated computers automatically make all corrections and compensations. That’s why CME can guarantee an overall system accuracy with the minimum degradation of accuracy and possibility of error and still provide both actual flow rates and standard flow rates.