Metex 3200U Ultrasonic Flow & Level Monitor - Manual (Page 41)

APPENDIX B - APPLICATIONS BACKGROUND
Conditions in the tank or channel where the ultrasonic sensor is installed can affect the performance,
range and accuracy of the system. The following notes are for general reference. Contact AquaMetrix or
your local representative for specific information on your application.
FOAM - Solid or dense surfaces such as a smooth liquid surface will give the best echos in an
ultrasonic level measuring system. Foam acts as a sound insulator and may eliminate, or reduce the
strength of an echo. Measurement range may be reduced in a system where foam is present. Ultrasonics
are not recommended where thick dense foam is continually present. Intermittent or thin layers of light
foam (1/8 in. or less) can generally be disregarded. Use a stilling well in open channel applications.
LIQUIDS - The Ultrason is ideal to monitor tank liquid level or inventory. Caustic, corrosive or very
viscous liquids can be monitored without contacting the liquid.
SOLIDS - The Ultrason will measure most granular material and powders as well as liquids. Powders
will not generally provide the same echo strength as liquids. Therefore maximum expected range should
be reduced to approximately 20 feet (6 m) for powders. There are many exceptions to this rule and
installation of a test system is recommended when in doubt.
DUST - Any obstructions to the sound will affect performance of the system. In silo’s where heavy
concentrations of dust are expected ultrasonics may not work. Where moderate dust is encountered
care should be taken to mount the sensor in a position where dust accumulation will be minimized and
where the sensor can be cleaned if necessary.
SENSOR TEMPERATURE - The standard sensor model US2 supplied with each Level & Flow
Monitor includes a built-in temperature sensor. The Ultrason automatically compensates for temperature
fluctuations to retain high accuracy. Note the operating temperature ranges listed in the product
specifications section. Do not exceed the sensor temperature ratings or damage may occur.
ELECTRONICS TEMPERATURE - Note operating temperature ranges listed in the product
specifications. Temperatures higher than the maximum shown can reduce the operating life of the
electronics. Moisture condensation from those temperatures below the range shown can also damage
electronics components. In cold or outdoor environments the optional factory-installed enclosure heater
and thermostat is recommended.
NOISE - Because the Ultrason’s sensor operates at high sound frequency, regular process noise or
vibration will not affect the system. Sensors installed in close proximity to one another in the same tank
may “cross-talk” and should be synchronized.
VAPOUR - May affect but it can be compensated for by calibration in-situ. Severe vapour stratification
can cause false echoes. Variable vapour cannot be compensated.
CHEMICAL COMPATIBILITY - The Ultrason is constructed of very durable materials with broad
compatabilities. Tank contents should be checked for their compatibility with PVC. An all-teflon
sensor is available for corrosive applications.
AquaMetrix
Ultrason
Page 41