The Digital Flow ISX878 ultrasonic
flow transmitter combines the simplicity of a loop-powered
meter installation with proven, advanced clamp-on ultrasonic
flow transmitter technology. It provides customers with an
economical solution for flow measurement in pipes up to 16 in
(400 mm).
Intrinsically Safe
The Digital Flow ISX878 provides a low cost solution for
non-intrusive liquid flow measurement in your hazardous
locations. The Digital Flow ISX878 is able to achieve an
intrinsically safe rating by significantly reducing the amount
of energy required to drive the ultrasonic transducers.
Reducing the drive voltage by a factor of 10 could only be
made possible through advancements in the ultrasonic
transducers. The new ISXDR transducers are considerably more
efficient than our previous piezoelectric models that led the
market over the past two decades.
Lower Cost of Ownership
Intrinsic safety reduces installation costs by eliminating
the need for heavy explosion-proof junction boxes and conduit.
The reduced power usage also allows the Digital Flow ISX878 to
be a loop-powered device, which saves on installation costs.
This becomes more important where hazardous locations have
significantly higher costs for running power cables for an AC
or DC unit. The Digital Flow ISX878 uses an available twisted
pair of instrument cables, fed through a safety barrier, to
power the unit. Since the meter clamps onto the outside of the
pipe, there is no need to shut down a line to install the
meter or to service it. The robust electronics and transducers
have no moving parts to break or wear down, so annual
maintenance can be significantly reduced, if not entirely
eliminated.
Two-Path Model
An optional second channel provides the capability to
obtain two-path averaging of the flow measurement, at a single
point for increased accuracy.
Uses the Transit-Time Flow Measurement Technique
The Correlation Transit-Time™ technique uses a pair of
transducers with each transducer sending and receiving coded
ultrasonic signals through the fluid. When the fluid is
flowing, signal transit-time in the downstream direction is
shorter than in the upstream direction; the difference between
these transit-times is proportional to the flow velocity. The
Digital Flow ISX878 measures the time difference and uses
programmed pipe parameters to determine flow rate and
direction.
