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TTFM 6.1 Transit Time Flow Meter
SENSOR MOUNTING LOCATION
The position of the sensor is one of the most important considerations for accurate flow measurement.
The same location guidelines apply to Transit Time as most other flow meter technologies.
VERTICAL OR HORIZONTAL PIPE - Vertical pipe
runs are acceptable, and the transducers can be
mounted in any orientation around the pipe.
Downward flow should be avoided in case the pipe
becomes partially filled or aerated. On Horizontal
pipes and liquids with high concentrations of gas or
solids, the sensors should be mounted on the side (1 to
5 o’clock positions) to avoid concentrations of gas at
the top of the pipe, or solids at the bottom.
STRAIGHT RUN REQUIREMENTS – For best
results, the transducers must be installed on a straight
run of pipe, free of bends, tees, valves, transitions,
insertion probes and obstructions of any kind.
For
most installations, ten straight unobstructed pipe
diameters upstream and five diameters
downstream of the transducers is the minimum
recommended distance for proper operation.
Additional considerations are outlined below.
• Do not, if possible, install the transducers downstream from a throttling valve, a mixing tank, the
discharge of a positive displacement pump or any other equipment that could possibly aerate the
liquid. The best location will be as free as possible from flow disturbances, vibration, sources of heat,
noise, or radiated energy.
• Avoid mounting the transducers on a section of pipe with any external scale. Remove all scale, rust,
loose paint, etc., from the location prior to mounting the transducers. A sanding block is included with
every meter to facilitate proper pipe preparation.
• Do not mount the transducers on a surface aberration (pipe seam, etc.).
• Do not mount transducers from different ultrasonic flow meters on the same pipe.
• Do not run the transducer triaxial cables in common bundles with cables from other instrumentation.
You can run these cables through a common conduit ONLY if they originate at the same flow meter.
• Never mount transducers under water.
IMPORTANT NOTE:
In some cases, longer straight runs may be necessary where the transducers are
placed downstream from devices which cause unusual flow profile disruptions or swirl. For example:
modulating valves, or two elbows in close proximity and out of plane.
Summary of Contents for TTFM 6.1
Page 2: ...Note This page has been left blank intentionally ...
Page 5: ...Page 5 TTFM 6 1 Transit Time Flow Meter 100 240 VAC Meter CONNECTIONS ...
Page 27: ...Page 27 TTFM 6 1 Transit Time Flow Meter TYPICAL SENSOR INSTALLATION ...
Page 53: ...Page 53 TTFM 6 1 Transit Time Flow Meter SENSOR MOUNTING COUPLING RECOMMENDATIONS ...
