Ultrasonic Flowmeters

High-performance CALDON LEFM ultrasonic flowmeters deliver a rapid ROI and increased uptime in custody transfer, allocation, and leak detection applications. The products’ patented internal designs, measurement precision, compact footprint, and low-pressure drop help operators reduce measurement uncertainty and operating costs.

Following are the different type of flowmeters:

Liquid Hydrocarbon Ultrasonic Flowmeters

Backed by more than 50 years of experience and a history of technological firsts, the Cameron portfolio of CALDON LEFM ultrasonic flowmeters combines experience, innovation, and proven technology into the broadest offering of custody transfer, fiscal, check metering, and leak detection innovations for the liquid hydrocarbon industry.

The CALDON LEFM flowmeter series accommodates the largest range of applications, including high-viscosity crude oils and LNG. CALDON LEFM flowmeters for liquids have become the benchmark around the world. Leveraging expertise from one of the most advanced liquid hydrocarbon calibration laboratories, Cameron offers the most complete capabilities to fit all customer application and service needs.

Gas Hydrocarbon Ultrasonic Flowmeters

CALDON LEFM ultrasonic flowmeters provide the industry with durable, stable, and low-cost-of-ownership ultrasonic measurement options. Cameron is constantly developing cutting-edge ultrasonic technology to better meet industry demands for custody transfer. Our multipath inline ultrasonic flowmeters are backed by more than 50 years of experience and a history of technological firsts for their use.

Designed to help satisfy customer needs with the broadest product range for custody transfer of natural gas, CALDON LEFM flowmeters provide

improved meter reliability over a wide range of application conditions
improved safety for technicians when replacing transducers
simplified installation, reduced meter footprint, and overall metering section weight
reduced maintenance.

High-Viscosity, Low-Flow Ultrasonic Flowmeters

Measuring oils with high viscosity and/or low flow conditions may involve operating at Reynolds numbers below 10,000, in the laminar and transition flow regimes. Full-bore ultrasonic flow meter performance traditionally has degraded for Reynolds numbers below 10,000 because the liquid velocity profile erratically switches between laminar and turbulent characteristics. The CALDON LEFM 280CiRN Series eight-path reduced nozzle liquid ultrasonic flowmeter has a reduced bore design modelled after flow nozzle technology in which the liquid velocity profile is stabilized in the throat by forces much larger than the forces imposed by fluid viscosity. The meter stabilizes the flow profile while preventing boundary layer separation under all operating conditions, greatly improving performance.

The eight-path design of the LEFM 280CiRN liquid ultrasonic flow meters resists installation errors better than any other ultrasonic meter. The cross-plane acoustic paths make the meter immune to the effects of swirl and eliminate the need for an upstream flow conditioner. The effects of swirl on the four paths in one plane are equal and opposite to the effects of swirl on the four paths in the second plane. When the velocity readings from all eight paths are averaged together, any effects from swirl are cancelled out. The design also minimizes the requirement for upstream/downstream pipe runs.

The elimination of a flow conditioner and the need for shorter lengths of upstream pipe reduce the installed cost for the LEFM 280CiRN Series liquid ultrasonic flow meter. This elimination also means lower overall pressure loss, which equates to annual savings in pumping costs.

Our LEFM 280CiRN liquid ultrasonic flow meter has improved repeatability compared to standard full-bore meters and also can be considered for applications when the meter is to be verified in-situ using a prover to reduce the number of runs required.


  • Standard Features
  • Reduced-bore design for high performance under laminar, transition, or turbulent flow
  • Excellent repeatability that reduces the number of runs required to verify the meter in-situ with a prover
  • Electronics that can be integrally or remote pipe mounted
  • Available in 6″ to 36″ sizes
  • ±0.10% linearity over 15:1 nominal flow range for all sizes
  • No limit on operating Reynolds number
  • OIML R 117-1 Edition 2007 (E); Accuracy Class 0.3

LNG Ultrasonic Flowmeters

Cameron was the first company to develop an ultrasonic flowmeter for dynamic custody transfer of LNG. Our CALDON LEFM 280CiLT-R Series eight-path low-temperature liquid ultrasonic flowmeter received the 2010 Innovation Award by the readers of Flow Control magazine. The CALDON LEFM 280CiLT liquid ultrasonic flowmeter offers many benefits for measuring LNG, although the major advantage is the eight-path design. The two-plane arrangement of the eight acoustic paths makes the meter insensitive to velocity profile asymmetry and swirl. In addition, the LEFM 280CiLT does not require a flow conditioner and needs minimal straight runs of pipe upstream/downstream of the meter.

In 2005, Cameron supplied a CALDON LEFM 280CiLT-R liquid ultrasonic flowmeter to a joint ExxonMobil/ConocoPhillips project designed to assess flow technologies for LNG projects. These tests confirmed the effect of the swirl was equal and symmetrical between the two planes and that averaging the velocities among the eight paths eliminated any bias due to swirl.

Being able to measure LNG with higher accuracy than traditional methods using the CALDON LEFM 280CiLT-R liquid ultrasonic flowmeter can result in real savings. The monetary value of the LNG on an average tanker is approximately $31.9 million, based on an average tanker size of 266,000 m3 and an April 2010 estimated value of LNG of $120/m3. An overall improvement of just 0.10% in uncertainty by using the CALDON LEFM 280CiLT-R liquid ultrasonic flowmeter can result in a potential savings of $319,000 per tanker load. The elimination of a flow conditioner lowers overall pressure loss, which equates to additional annual savings in pumping costs or faster ship-loading times.


Standard Features

  • Insensitivity to swirl
  • Electronics are remote mounted
  • Available in 6″ to 36″
  • ±0.10% linearity over the nominal flow range
  • ±0.18% extrapolated on LNG volumes from calibration on water or light oil as documented in NMi Report No. CPC10200743
  • OIML R81-NMI; C-SP/60667-HrW/RAP; Accuracy Class 0.3

Nuclear Ultrasonic Flowmeters

The fixture precisely locates the transducers on the pipe surface to form four acoustic paths. Two pairs of transducers form cross paths, and the remaining transducers form diagonal paths. Acoustic pulses are sent back and forth between pairs of transducers. The transit time of the pulses is measured and, along with the pipe dimensions and acoustic properties of water, are used to determine the average axial velocity. The axial fluid velocity, the cross-sectional area of the pipe, and the meter velocity profile constant are used to calculate volumetric and mass feed water rates. The CALDON LEFM 2010FE nuclear feedwater temperature and flowmeter measure mass feedwater flow to within ±1% and average bulk feedwater temperature to within ±2° F (±1.1° C).

Our CALDON LEFM 2010FE nuclear feedwater temperature and flowmeter system consist of at least one electronics unit, fixture, transducers, and transducer cables per feed water loop or common header. The system also can include a router to perform totalizing and communication functions. Multiple analogue (4 to 20 mA) outputs and RS422/485 serial communications are provided for data acquisition and interface to plant equipment.

The CALDON LEFM 2010FE nuclear feedwater temperature and the flowmeter is a highly reliable system that requires little maintenance and provides preventable diagnostic indicators. Continuous online testing verifies the system is operating correctly and within the specified accuracy envelope. Any detected faults that cause system operation to be outside the specified accuracy will generate a failure indication via the serial output. Means for fault isolation are provided should a failure occur. In addition, the system has a modular hardware design that allows any defective components to be isolated and repaired quickly.


Standard Features

  • Onsite installation of fixtures and transducers
  • System commissioning
  • Collection of baseline design data
  • Customer training
  • Field testing
  • Uncertainty analysis in accordance with ASME PTC 19.1
  • The system consists of an external fixture and transmitter
  • Measures mass feed water flow rate and temperature to support the calculation of thermal power
  • Plant hydraulic conditions simulated during water calibration using the master system

Hydro Power Ultrasonic Flowmeters

8001 transducers and 8002 feedthrough assemblies are designed for installation on exposed pipes and penstocks from 42″ to 27 ft in diameter. This is a 1-MHz transducer suitable for high-accuracy measurement in large pipes. The feedthrough assembly is designed to allow retraction and removal of the transducer while the pipe is under pressure. In addition, the 8001/8002 incorporates dual retaining pins and a tamper-resistant pin guard/retainer, features that are not available elsewhere.

8003 transducers and 8004 feedthrough assemblies are designed for installation on exposed pipes and penstocks from 20″ to 48″ in diameter. These assemblies are specifically designed for use in smaller pipes where protrusion of the transducers into the flow is minimized in order to maintain high measurement accuracy. However, the transducer still retains radial feedthrough for ease of installation on existing pipes. Additionally, the feedthrough design utilizes a standard Thread-O-Let® fitting.

CALDONHydro Transducers for Buried Pipes and Tunnels

8010 transducers and 8011 mount assemblies are designed for installation in buried pipes and tunnels from 5 ft to 25 ft in diameter. This is a 1-MHz transducer suitable for high-accuracy measurement in large conduits.

8005 transducers and 8006 mount assemblies are designed for installation in buried pipes and tunnels from 8 ft to 35 ft in diameter. The 8006 is a low-profile mount assembly designed to minimize flow disturbance over the transducers. The assembly incorporates a waterproof connector to allow transducer replacement without splicing or rerouting cables.