WHAT'S NEW ABOUT RADARTRON 2250D?

Scale-Tron's well known RadarTron microwave moisture sensor has been upgraded in several important ways, as follows:

Digital bidirectional communication through both RS232 and RS485 connections, to transmit moisture readings and allow menu-style setup and calibration.  RS 232 allows easy connection to most computers and PLCs while RS485 can communicate reliably up to 4000 ft, eliminating the need for extra repeaters.  Any number of sensors can share the same RS485 line in daisy-chain fashion, to a single computer or PLC port.  An optional module converts this back to either RS232 or USB for connection to the computer.  The digital interface is fully compatible with Command Alkon and other batch controllers.

Totally new circuit board with digital processing, allowing the filtering and averaging parameters to be adjusted when necessary for special applications.

Shorter body, sealed construction and smaller mounting flange, allow installation in crowded spaces while still providing the 'reach' that is sometimes needed to get into the flow region

Analog output;  both 0-20 and 4-20 mA are selectable.  If 0 - 10 volt output is desired, a resistor can be connected at the receiving end to convert the current signal into a voltage signal,  giving higher accuracy than with a standard voltage signal.

Temperature sensor situated near the faceplate gathers an accurate average temperature of the material surrounding the faceplate.  This is used to compensate for the small change in water's dielectric constant with temperature, improving accuracy over the temperature range, as well as being available through the digital output for use by the computer.

Low material level output;  the previous 1400C model sensed when the faceplate was uncovered and froze the moisture reading, preventing an abnormally low reading from spoiling the batch in process.  2250D has this same feature but also allows this output to be used for external alarms.  The junction box is available with a relay for this purpose.

Multiple material calibration;  up to16 separate material calibrations are available, for use in different materials.  This feature allows 2250D to be used in those awkward applications where different materials are used from time to time in a single bin.

24 volt power; 2250D will run from the batching controller or any inexpensive unregulated power supply between 11 and 30 volts DC.

CALIBRATION SYSTEM

Calibration is a tedious chore that has to be accomplished.  The 2250D sensor is precalibrated with 'average sand' in our test lab.  Because materials differ, however, even in building sand, each sensor should be checked after installation and trimmed if not up to par.

In place of the 1400C's awkward internal calibration pots, 2250D is sealed and calibration is done through the digital interface.  If you are using the digital interface as your main connection to a PC computer controller, all you need for calibration (and local moisture display) is the Windows software utility provided with the sensor or, if lost, the Hyperterminal software that comes with Windows.  This is found through the Start menu under Accessories, Communications.  If you are using the RS485 or analog connection, or are connecting to a non-PC system, such as a PLC, use the Programming Cable to connect to a Windows computer, laptop or PDA.

Once on-line, the setup and calibration menu guides you through the steps.  You need several readings along with the true moisture values obtained from oven-dry or bakeout tests, over a wider range of moisture than will be used in practice.  Once these values are entered, calibration is a click away.

For multiple materials, this process is repeated for each material.  Yes, it's tedious, but anyone who tells you that they have a simpler system is just not telling the truth.  There is no substitute for proper calibration;  no system will perform accurately without it.

       NEW MIXTRON SENSOR

Now that we have RadarTron 2250D under our belts, we can concentrate on its sister - Mixtron D.  We are presently finalizing this new sensor, which has most of the advantages above plus a few of its own.  Compared with our present Mixtron sensor, the digital Mixtron has signal averaging built in, with programmable parameters for unequalled accuracy in most mixers.  General appearance, cables and connections are similar to RadarTron 2250D.

Bin low relay
Gives dry contact output for connection to alarm circuit or PLC input, 24 to 250 volt, UL/CSA/CE.

Digital Display unit
Unchanged from 1400C model, this display connects to the 4-20mA analog output to give a digital moisture display.  Available as panel mount or in waterproof enclosure.