Veris Verabar Brochure - Manual (Page 2)

Superior Signal Stability
and Greater Resistance to Clogging
Clogging can occur in low pressure ports located in or near the partial vacuum
at the rear of the sensor. The Verabar design locates the low pressure ports
on the sides of the sensor, forward of the fluid
separation point and turbulent wake
area. This virtually eliminates clogging
and produces an extremely
stable signal.
Rough Surface Smooth Surface
± 1 / 2 Percent
3%
2%
1%
0%
-1%
-2%
-3%
0% 5% 10% 15% 20% 25%
Percent Blockage
Per
cent Deviation fr
om the Published K
Air Tests
Water Tests
0.5 Percent
Error Band
Lower Drag and Extended Turndown
Golf balls fly farther because they have a dimpled surface
that lowers aerodynamic drag.
The grooves and roughness on the Verabar’s frontal surface
apply the same principle. This simple design feature relieves the
partial vacuum at the rear of the sensor, reducing the pressure drag.
This extends the accuracy and rangeability to very low velocities.
The Most Accurate and Reliable
Technology for Measuring Gas, Liquid
and Steam
Developed from aerospace technology, the
Verabar averaging pitot flow sensor provides
unsurpassed accuracy and reliability.
With its solid one-piece construction
and bullet shape, the Verabar
makes flow measurement
clog-free and precise.
The unique sensor shape
reduces drag and flow
induced vibration.
And the location
of the low
pressure
ports elimi-
nates the
potential for clogging
and improves signal
stability.
Test Data Summary
From Veris Research…True Performance in DP Flow Measurement
In God We Trust …
All Others Bring Data
The unique and exclusive break-
through in improved accuracy
derived from the development of
a verified theoretical model
predicts the Verabar flow
coefficients. This elimi-
nates the need for
calibration tests to
characterize the
flow coefficients.
Without such a model,
the uncertainty of the flow
coefficients is dramatically
increased and expensive
calibration may be required.
Empirical test data from indepen-
dent laboratories verified the theore-
tical model and flow coefficients as a
constant, independent of Reynolds number
and within ±0.5% of the predicted value. The
derivation of the theoretical model and test data
is published in the Verabar Flow Test Report (ED-100).