CALDON LEFM CheckPlus C and CheckPlus M Flow Meter


CALDON LEFM CheckPlus Feedwater Flow Meter Systems provide the highest accuracy feed water flow measurement available for nuclear power plants. Our CALDON LEFM CheckPlus Feedwater Flow Meters use well-proven ultrasonic transit-time technology to measure feed water flow with a typical uncertainty of 0.3%, regardless of upstream hydraulic conditions. By using this figure in 10CFR50 Appendix K safety calculations, rather than the 2% required for traditional metering technologies, plant operators can increase power generation up to 1.7%, which translates into millions of dollars in additional revenue per year.

In existing nuclear power plants, the CALDON LEFM CheckPlus Feedwater Flow Meter has been approved by the US Nuclear Regulatory Commission (NRC) and other international regulators as a basis for measurement uncertainty recapture (MUR) uprates to 1.7%. 

In new plants, the CALDON LEFM CheckPlus Feedwater Flow Meter Systems can completely replace other nuclear feed water flow measurement technologies, allowing for increased power generation over the full life of the plant. The meter’s ability to correct for cross flow or swirl also allows for decreased construction costs by eliminating special piping layouts and valves typically required to provide specific flow conditions for other flow meter technologies.

The LEFM CheckPlus Flow Meter also meets mass flow measurement requirements of ASME Performance Test Code 6 (PTC-6) without modifications, providing significant cost savings at the time of plant startup. The benefits extend well beyond the compliance test since the system allows continuous monitoring of the power conversion system for the life of the plant.


Standard Features

  • Guaranteed highly accurate flow measurement
  • Accuracy specifications which include effects of all parameters that could impact performance
  • Verifiable performance online via continuous self-checking circuitry
  • Easy to use, intuitive touchscreen offering graphical displays of real-time data and historical trending
  • Continuous preventative diagnostic software
  • Independent system testing and verification at Alden Laboratories in plant-specific hydraulic piping model
  • Eight-path spool piece for installation in tight piping close to elbows, tees, etc., corrects for hydraulic effects on meter performance
  • All-welded spool piece design
  • Simple transducer replacement that does not interrupt flow

Product resources

Manuals & Support

CALDON LEFM CheckPlus-C feedwater flowmetering systems Manual


CALDON LEFM CheckPlus-C feedwater flowmetering systems User Guide


CALDON LEFM CheckPlus-M feedwater flowmetering systems User Guide


Marketing collateral

CALDON LEFM CheckPlus feedwater flowmetering system Product Sheet

Product datasheet

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