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 Strong
rotor design
Excellent
repeatability for batching
Simple
robust design
Devices
available for sanitary applications
Low
cost |
The ABLE range of turbine flow meters offers
high accuracy and reliability. A ferritic,
stainless steel rotor revolves within a non magnetic
housing on the outside of which is located a pick
off coil containing a permanent magnet. As the rotor
blades pass the tip of the permanent magnet, the reluctance
of the magnetic circuit is changed and a small ac
voltage is generated in the coil. The frequency of
the ac voltage is proportional to flow rate, and the
total number of pulses produced represents total flow
passed through the meter.
The electrical signal is a sinusoidal
pulse of minimum height 50mV peak at lowest flow
rate, rising to 800mV peak at max flow rate. For
normal transmission distance pre-amplifiers are
not essential since pulse shaping and conditioning
are carried out in the appropriate electronic readout
unit.
In cases where heavy electrical
noise is present or where transmission distances
are over 500 metres, pre-amplifiers of standard
or intrinsically safe design are available as head
mounted weatherproof units and loop powered.
Remote flow rate indication, alarms,
totalising and batch control functions are available
utilising our wide range of secondary electronic
instruments, the subject of separate brochures.
The flow meter may be located some considerable
distance from the associated secondary instrument.
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Installation
& Use |
For
best results the flow meter should be installed
well away from heavy current carrying cables and
with control valves etc. located downstream of the
meter. A length of straight pipe of bore equal to
the meter inlet should be provided, preferably 10
diameters in length, and if possible containing
flow straightening vanes at the inlet end. Turbine
meters are sensitive to swirl and any pipe swirl
present upstream may cause a change in meter factor.
Strainers should be provided to
minimise the risk of damage due to small solids
in suspension.
Meters may be installed in any
attitude, but the flow direction and mounting attitude
should be advised at the order stage if other than
horizontal. Varying densities have no appreciable
effect on the accuracy of axial flow turbine meters
so far as volumetric flow is concerned. If readout
is required in mass flow terms, we can supply density
or temperature compensation equipment to automatically
correct for density variation. All turbine meters
are to some extent sensitive to viscosity changes
and any likely viscosity variation should be advised
at the order stage.
For further information please
contact us
here
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