Exact Dual Rotor
Turbine Flow Meters

DESCRIPTION
The Cox Exact Dual Rotor Turbine Flow Meter is the pinnacle of
turbine meter technology that delivers results not attainable
with single rotor designs. The Exact meter’s hydraulically coupled
helical dual rotor design provides exceptional performance and
many unparalleled benefits. The dual rotor design extends the flow
measurement range, due to the high incidence angle on the
second rotor, resulting in turndowns of 120:1 on the smallest
meter to 500:1 on larger meters. This exceptional flow range allows
universal viscosity curves to blend over a 60:1 turndown range.
This wide flow range often eliminates the need for more costly
manifold systems.
Swirl effects on the leading rotor will have an opposite effect on
the trailing rotor. Therefore, by summing (or averaging) both rotors,
it will virtually cancel out rotor acceleration, eliminating the need
for flow straighteners. With flow straighteners, the ratio of the two
rotors can be monitored to determine bearing health. Reduced
friction ceramic ball bearings, combined with a unique embedded
pickoff system, impervious to vibration, makes the Exact Dual Rotor
design ideal for onboard vehicle, flight and critical applications.

Features
Dual Rotors

Benefits
Superior absolute accuracy and wider
turndown ratios are achieved. They also
cancel out swirl effects.
Exceptional speed-of-response, with reduced
pressure drop
Provide less friction and can be used in water
and hydrocarbons

Helical Rotor
Design
High-Performance
Ceramic Ball
Bearings
Extended UVC
Greater turndown flow range, while reducing
Range
the need for manifold systems
High Shock Design Internals are rigidly clamped against a step in
the bore, with rod and nut torqued design.
Facility with
Third party audits to ensure calibration
NIST traceable
uncertainty. Laboratory correlation to verify
standards
that all calibrators produce the same result.

CALIBRATIONS
Calibrations are accomplished by utilizing various blends of solvent
and oil to simulate actual fluid conditions. For varying process
temperature conditions, multiple viscosity calibrations are used to
develop a universal viscosity curve. UVC calibrations enable a flow
computer to track temperature and compensate for fluid viscosity.
Flow Dynamics tailors calibrations to replicate process conditions,
so the meter is characterized to provide the best possible accuracy.
Calibrations are performed by our Flow Dynamics NVLAP
(Lab Code 200668-0) accredited calibration facility located in
Scottsdale AZ, which uses primary standard calibrators, offering
uncertanties of ± 0.05 percent of reading with ± 0.02 percent
repeatability. Users can be assured that Cox Precision Meters come
with a best-in-class calibration, traceable to NIST standards.

APPLICATIONS
OEM flight and hydraulic component testing

•t

Precision industrial blending processes

•t

Engine test cells and test stands

•t

Precision flow monitoring

•t

On-board aerospace and automotive testing

•t

Custody transfer

•t

Correlation standards

•t

Flow Transfer Standard Master Meter

•t

CXX-DS-00172-EN-04 (April 2014)

•t

Custom flight or industrial OEM packaging

Product Data Sheet