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Advanced Data Bulk Dielectric Transducer with Radio Telemetry The RDNET-BDT is a revolutionary micro-power state-of-the-art “bulk dielectric” sensor that can be applied to a wide range of applications where there is need to differentiate between water, dilute acidic/alkali solutions, milk and other similar relatively high permeability substances which displace or are displaced by a relatively low permeability substances such as air, oils, fats, waxes, gases, steam, etc. Applications include: 

Pollution Containment Valve Automatic Activation

High Level Alarms

Oil Blanket Alarms for Oil Interceptors

High Water Alarms

Flood Alarms

FOG Blanket Alarms (Fat, oil and grease) for Fat Traps

Blocked Sewer Detection

CSO Spill Detection

The transducers are configured to operate with our integrated battery powered wireless transmitter that use DSP to converts the complex output waveform from the transducers into a simple high level, low level signal that can operate remote relay contacts for process control or to initiate an alarm. The transducers housed in a chemically inert, food safe, Acetal plastic housing that fully encapsulated to IP68 standards. Unlike traditional conductivity and float switch probes the lack of moving parts and electrical contacts makes them virtually immune from fouling and ragging.

Both the transducers and transmitters can be installed in either above or below ground locations. The latter includes drains, sewers, oil interceptors, septic tanks and fat traps. When mounted above ground, the radio telemetry can communicate over distances ranging from a hundreds of meters to many km. From below ground, depending upon the construction of the access chamber and the antenna type used, distances from a few tens of meters to up to 200m can achieved eliminating the need for messy, disruptive and costly trenching and cable ducts. The communication distance can be increased further by the use of an optional repeater. Design & Copyright Radio Data Networks Limited 2011 Issue 1.0

Target Industry Sectors Include: 


Food Preparation (Available in blue food safe enclosure)

Water Utility

Flood Defence

Pollution Prevention & Control

Electricity Distribution

Brewing & Distilling

Slaughter Houses & Abattoirs



Depending upon the sampling interval, the complete system can be battery powered for over a decade, giving the system an extremely low whole of life carbon footprint.

Fig 2: Bulk Dielectric Transducer Complete with Wireless Transmitter Configured for use in Drains and Interceptors

Design & Copyright Radio Data Networks Limited 2011 Issue 1.0

Provisional Specification RDNET 1000 BDT: Sensing Technology Bulk Dielectric High Permeability/Dielectric Constant Low Permeability/Dielectric Constant

Er > 50 Er < 10

Current Consumption Operating voltage

< 20uA @ 3V 2.5 to 14V dc

Battery Life

Up to 10-years depending upon Sampling rate and transmission interval

RF Transmitter

Licence Free VHF for UK and Ireland UHF for UK, EU and CENELEC RF emissions to EN-300-220-1 & R&TTE Directive CE Output Power Antenna Dependant <=+10dBm

Electrical Safety EN60950 ATEX (optional) Mechanical BDT: Material â&#x20AC;&#x201C; Acetal C food grade blue Length 120mm Diameter 35mm RF Transmitter: ASA blue or ATEX black 110mm height (ex antenna) 90mm width 50mm deep Operating Temperature BDT RF Unit

-20C -20C

to to

+ 100C +55C

Ingress Protection IP68 Fully encapsulated â&#x20AC;&#x201C; non serviceable

Design & Copyright Radio Data Networks Limited 2011 Issue 1.0

Oil Interceptor High Oil Blanket Monitoring Example: The diagram below Fig 3 depicts a typical oil interceptor alarm with pollution containment valve on its outfall under the control of the RDNET-BDT.

SMS Text Alarm Message


Pollution Control Valve Panel

Oil Interceptor

Fig 3: The RDNET 1000 BDT Used for Monitoring Excessive Blanket Thickness in Oil Interceptors or a sudden Spill

Disclaimer: Information contained within this specification is given in good faith. Radio Data Networks Limited or Environmental Innovations Limited cannot be held responsible for any errors or omissions contained within. It is up to the user to confirm operation and the suitability of the product by trial before putting into service. For life or mission critical applications it is important to install a backup system/s, therefore no responsibility whatsoever can be accepted where failure to do so has resulted in losses or damages. Remember no instrument is infallible, all require periodic calibration and testing and all systems should be designed to fail safe.

Design & Copyright Radio Data Networks Limited 2011 Issue 1.0


The transducers are configured to operate with our integrated battery powered wireless transmitter that use DSP to converts the complex outp...