Paddy - Screen break detection

You are here:Home · Products

Paddy -
Screen break detection

Paddy is a particle sensor for on-line monitoring of coarse grain in the flow.
If multiplied coarse particles are detected in the product flow, an alarm is given.

  • Monitoring of the material flow regarding the presence of oversized particles
  • Uses state-of-the-art microwave technology in combination with intelligent evaluation software
  • Can be installed in free-fall pipes downstream from screening or grinding systems
  • Possibility of trend showing for grain size
  • Fast detection of coarse particles, for as little as 10 % of the mass flow



The Paddy sensor can be used in all processes where solids are ground and screened. At the output of these processes there are always at least two fractions: the fine particles and the coarse particles. If a screen break occurs, this has led to the production of large rejects or an increased workload by re-screening.

The paddy sensor is installed in the outlet of the fine particles and detects reliable in case of a screen break.


The patented measuring method consists of two microwave sensors, which are installed in a free-fall pipe. Due to the arrangement of two baffles, all particles in the product flow begin to fall at the same speed. In the following fall distance the velocities of the individual particles are considered.
If speeds in the higher range are detected, this immediately indicated the presence of larger particles. In this way, a screen break can be detected quickly.

Mounting and Installation

At the selected installation site, two sensor sockets are welded at the required distance. Then a 20 mm borehole is drilled through the sensor socket and through the tube wall. Thereafter the sensor is adapted to the wall thickness, inserted and fixed with the help of the union nut. In addition, two baffles must be used in front of the sensor in order to achieve a constant speed of the material flow.

Technical Data

Sensors Measurement principle Microwave
  Measurement range Particle sizes up to 10 mm -
larger sizes on request
  Housing material Stainless steel 1.4571
  Protection type IP 65, dust explosion zone 20 or
gas explosion zone 1 (optional)
  Ambient operating temperature Sensor tip: -20 ... +80 °C
Optional: -20 ... +200 °C
Sensor element: 0 ... +60 °C
  Max. operating pressure 1 bar
  Operating frequency K band 24.125 GHz, ±100 MHz
  Transmission power Max. 5 mW
  Weight 1.3 kg
  Dimensions Ø 60, Ø 20, L 271 mm
Transmitter (DIN rail converter) Power supply 24 ± 10 % V DC
  Power consumption 20 W / 24 V
  Protection type IP 40 to EN 60529
  Ambient operating temperature -10 … +45 °C
  Dimensions 23 x 90 x 118 (W x H x D)
  Weight Approx. 172 g
  Connection terminals cable cross-section 0.2 – 2.5 mm² [AWG 24-14]
  Current output 4 … 20 mA, load < 500 Ω
  Switch output measurement alarm

Switch output error alarm
Relay output, either
NC (break contact) or NO (make contact) -
max. 250 V AC, 1 A
  Field bus communication ModBus RTU (RS 485)
  Data backup Flash memory

Quickfinder: What are you searching?