Dwyer UXF2 - Manual (Page 110)

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5.7.2. If keying is abnormal
Symptom Cause
Keying (buttons) not registering. z Hardware error. Refer to "Section 5.7.6. Remedying a hardware
fault".
Certain key is not responding.
Action is not as defined.
5.7.3. If measurement value is abnormal
Symptom Cause Remedy
z Connection between main unit and
sensor units (upstream,
downstream) are backwards.
Connect correctly. Minus (–) symbol
indicated on
measurement value.
z Switch cable connections (upstream & downstream).
z Straight part of pipe is inadequate Select where 10D upstream and 5D
downstream of detector is available.
z Pump, valve, tee, etc which
disturb the flow are located
nearby.
Separate them to at least 30D.
Measurement value
fluctuates excessively
while flow rate is
constant.
z Pulsation exists actually. Set the damping to longer response time.
Ultrasonic wave is not propagated into piping properly, so reading is held.
1. Installation is poor.
Measurement value does
not change with actual
rate change (LED lit red).
z Pipe specifications are
wrong.
z Sensor is mounted on
welding.
z Sensor mounting
dimensions are wrong.
z Silicone filler is not
applied properly when
mounting the sensor
z Sensor cable connection is
poor.
Upon checking, remove the sensor,
apply silicone filler, and slightly off-
position the sensor.
Sensor mounting is poor
z
Mounting dimensions.
z There is a gap between
sensor and piping.
z Mount the sensor in parallel with
pipe, allowing correct sensor unit
spacing.
z Mount the sensor properly so that
it is kept in close contact with the
pipe.
2. Pipe or fluid is problematic.
Not completely filled.
Locate a place which is completely
filled on the same piping line, and shift
the sensor there.
z
Mount the sensor at lowermost
position on piping line.
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BULLETIN F-70