Hydronix Double-Digital Sensor

Prior to an official launch at the (Feb. 2-5) 2010 World of Concrete in Las Vegas, Hydronix announces the release of Hydro-Mix VII, its next-generation,

Prior to an official launch at the (Feb. 2-5) 2010 World of Concrete in Las Vegas, Hydronix announces the release of Hydro-Mix VII, its next-generation, microwave moisture sensor for mixers and screw conveyors. After introducing the first microwave sensors for concrete plant equipment nearly 30 years ago, Hydronix continued to advance their development by implementing a digital measurement technique used in the current generation of sensors, i.e., Hydro-Probe II for aggregates and Hydro-Mix VI for chutes, screw conveyors, and mixers. Hydro-Mix VII builds on the latter, product engineers affirm, taking it to a new level via multiple improvements.

Signal processing, measurement Û Added digital signal processing (DSP) filters contribute to Hydro-Mix VII’s advancement over the previous model, since filtering is essential to minimizing signal noise generated by the application. In operation, the sensor may first see material, next a passing metal blade, and then an air void, attenuating signals that fall outside a ÎnormalÌ target range. Identification of what is ÎnormalÌ Û the material Û becomes increasingly difficult when, for example, an air void is created (seen as a vortex) in a rapid planetary mixer handling a highly viscous mix, particularly if the mixer is one-third full. Thus, DSP filters are combined with existing filtering parameters to further smooth the sensor’s signal, without loss of data. The DSP thereby maximizes attenuation of signal noise while preserving the sensor’s speed of response to material moisture changes.

Providing further control of the measurement signal, DSP filters may be configured to operate with or without existing filtering parameters. Although control to such a degree typically is unnecessary, sensor installers for the most demanding applications now can incorporate additional tools to ensure the system is easily configured to produce the smoothest signal with the fastest response.

The most dramatic Hydro-Mix sensor development, however, has been a fundamental change in measurement technology used to obtain moisture data from the material. In addition to measuring frequency shift with digital accuracy Û as before Û yielding extended linearity over a wide moisture range, the new Hydro-Mix VII now has the ability to accurately measure microwave-signal amplitude using a digital technique. Both frequency and amplitude are measured independently, unlike an analogue sensor that only ÎseesÌ the combined signal; and, the two separate digital measurements are then combined, using precise mathematical formulae to delineate various material properties. Overall, the manufacturer emphasizes, Hydro-Mix VII’s digital technology provides greater precision and accuracy than analogue-based sensors that measure combined frequency shift and change in amplitude of an attenuated microwave signal, as material with different moisture levels passes over the device.

Given the upgraded basis for signal processing, a greater degree of choice is available when configuring the new sensor. Accordingly, the Hydro-Mix VII offers three operating modes: the original ÎstandardÌ setting, suitable for nearly all applications, plus two additional modes to further improve either sensitivity or stability.

Temperature stability Û Hydro-Mix VII sensors are monitored during production and individually configured to ensure compliance with the manufacturer’s temperature-stability specification. Embedded in the software to ensure the highest level of reliability in a microwave sensor, product developers explain, performance has been driven largely by demand in fields requiring a higher degree of temperature stability than even the concrete and aggregates industries Û to the benefit of all users.

Ceramic faceplate Û The Hydro-Mix VII has been redesigned to include the strongest ceramic faceplate ever used in a Hydronix sensor, improving what the manufacturer notes is already considerable cost effectiveness. The improved design also facilitates easier and quicker changing of the ceramic, should damage occur. Regular cleaning and routine maintenance, the company adds, will enable the Hydro-Mix VII to last many years.

Two Analogue Outputs Û A second analogue output has been added, allowing the sensor to output two different readings simultaneously. Û www.hydronix.com
World of Concrete Booth N262