FlowCERT

Functional Description
The FlowCERT is non-contacting and operates on the principle of timing
the echo received from a pulse of sound in air, when used with the
revolutionary new DUET (Double Ultrasonic Echo Transducer) transducer
this provides a highly accurate calculation of flow, from the measured head
preceding the primary element.
Pulsar’s DUET is a completely new concept, employing two separate
ultrasonic transducers mounted at different heights above the measured head
within the Primary Measurement Device (PMD). Both transducers emit
sound pulses synchronously and the returning echoes are analysed in the
FlowCERT discriminating between the two signals so the time difference
can be calculated extremely accurately. All other effects, including
temperature, are irrelevant and can be eliminated. The FlowCERT then uses
this knowledge to dynamically calculate the distance to the liquid surface
resulting in accuracy which has never been seen before.
Flow calculations to the British Standard BS3680 are available within the
software together with calculations for a wide variety of other primary
elements. Also available within the unit is a customised 32 point
calibration routine which also permits the flow measurement of non -
standard flumes and weirs. For channels without primary elements the
FlowCERT even offers the option of connecting a Speedy Velocity Sensor
and performing the calculations of Flow Q = Velocity x area for a wide
variety of channel shapes.
The FlowCERT utilises the unique DATEM software (Digital Adaptive
Tracking of Echo Movement). This is a proven digital mapping technique
developed especially for the Pulsar ultra range. It gives the system edge
when identifying the “true target level” in the face of competing echoes
from such things as pipes or other obstructions.
The FlowCERT can measure from zero to 15 m from the transducer to the
surface being monitored, dependent on the transducer used.
The FlowCERT can show level, space, distance, head or flow on the
display. The relays can be programmed to activate alarms, pump starters, or
other control equipment. There are two isolated 4-20 mA outputs that can be
connected to a chart recorder or PLC, to monitor level, space or distance,
independently from that shown on the display. There is an RS232 port, so
that the FlowCERT can be operated remotely by a PC or other equipment.
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