| Tank Level for Measurement of Wax in Vat |
| Controlling Liquid Wax Levels
with Ultrasonic Sensors |
A Candle Manufacturer needed a new way of
measuring the level of candle wax in over 60
stainless steel tanks. Candle wax by its nature is
sticky, and very difficult to handle and clean if it
overflows the tanks. To get a correct indication of
the level in the tanks a non-contact sensor would be
the desired approach.
The Candle Manufacturer required a sensor that
could be quickly and easily mounted on the 250
gallon tanks without drilling additional holes. Also,
because of the nature of candle wax, the sensor
needed to be able to withstand high temperatures.
Each tank has two openings, one for mounting the
pump and a second for venting. A mounting
bracket was designed to mount the sensor over the
vent hole. The sensor was attached to the bracket
approximately 4 inches over the vent hole to allow
room for the material to vent to the atmosphere, and
cool somewhat before it came in contact with the
sensor's face.
As a beneficial side effect the opening adds 4" to
the tank span allowing the liquid level to come to
the top of the tank without entering the sensor's
dead band.
Automation Products Group, Inc. provided a
Ultrasonic Sensor for testing in this application.
This sensor was picked because of its small dead
band (4 in.), low cost, and excellent sensitivity. The
sensor provided the needed accuracy to give the
operators the level indication quickly.
Because of their reliability, and low cost the
Candle Manufacturer decided to purchase the sensors for all of their Candle Wax tanks (60+).
Once the initial calibration of the sensors was
complete, the sensors have provided accurate level
indications for over two years. |
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| Self-Contained Ultrasonic Sensors |
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Maximum range from 4 to 72 in. (0.1 to 2 m) |
|
Works on solids or liquids |
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Analog, digital and trip point outputs |
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AutoSense software available on most sensors |
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Internal temperature compensation available |
IRU series sensors use ultrasonic technology to
provide a noncontact method of detecting flow,
presence, level, volume, proximity and distance
measurements. This versatility makes them ideal for
a variety of applications. Ultrasonic sensors are not
affected by target surface, color or translucency and
they function extremely well in harsh environments.
When monitoring liquids, they are not affected by
changes in dielectric constant, specific gravity or
viscosity. The sensors are reliable, user adjustable
and require little or no maintenance. |
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