APG IRU-9400 user manual - Manual (Page 20)

IRU Series
Rev. B1 3/10
20
Automation Products Group, Inc.
APG...Providing tailored solutions for measurement applications
Tel: 1/888/525-7300 • Fax: 1/435/753-7490 • www.apgsensors.com • [email protected]
• Programming Sensor Parameters
The IRU series have the flexibility to be programmed for use in a wide range of
applications. Each of the programmable parameters is describe below.
Units: Determines the unit of measure to be used in the utility software.
Options: 1 = Feet, 2 = Inches, 3 = Millimeters
Blanking: Sets the distance, beginning at the sensor face, to the point where
the sensor will begin looking for target signals. All targets closer than the
blanking distance will be ignored. The blanking should never be set to less than
the minimum range specification of the sensor. Doing so may cause the sensor
to detect the transducer vibrations created during the transmit process, which
will cause the sensor to “lock up” at the blanking distance.
Setting the blanking to less than the minimum range specification is not
recommended, although it is sometimes helpful to set the blanking to a greater
value. For example, when mounting in a stand-pipe it is recommended that the
blanking be set to a distance so that it extends beyond the bottom of the pipe.
This helps prevent unwanted signals, which may be generated in the confined
space of a pipe, from being detected. Be aware that if the desired target moves
into the blanking distance, errors in measurement will occur.
Sensitivity: Controls the level of amplification, or gain, that is applied to
a returning signal from the target. The sensitivity setting is expressed as a
percentage; 0 to 100%. When possible, it is good practice to keep the sensitivity
as low as possible while still allowing the target to be reliably tracked. Keeping
the sensitivity low reduces the chances of picking up undesired target echoes and
can also help reduce any interference caused by electrical or acoustical noise.
Lowering the sensitivity also has the effect of narrowing the detection area, or
beam spread, of the sensor. Because sound waves travel better through cooler
air than through warmer air, if the sensor is setup when the temperature is cool,
and the temperature is expected to increase, the sensitivity setting should be
increased an additional 10 to 20% to accommodate future warmer temperatures.