Contrinex’s ultrasonic sensors are trusted by a meat-processing plant to check that bins are empty before washing. Their high performance and reliability enable the plant to increase its productivity and eliminate breakdowns when washing empty meat bins.

An ultrasonic sensor is mounted above the conveyor, looking down at the bins on a conveyor as they travel towards a wash machine. The sensor checks for meat residues, rejecting any contaminated bins before they can reach the automated wash station. The previous system was unreliable, resulting in breakdowns and frequent interruptions to the washing process.


An industrial meat-processing company conveys portions of meat around its factory in food-grade plastic tote bins. Between batches, the empty bins must be washed before reuse, however, some bins can still contain sizeable pieces of meat. If this meat is allowed to remain in the tray and enter the wash station, it can accumulate in the washing machine, causing blockages and breakdowns.

To prevent this, a sensor system must reliably detect the presence of meat residues in the bins as they travel along the conveyor. The sensor should identify all non-trivial residues and divert contaminated bins before they enter the washing station. The ideal system would require little or no regular maintenance, and ideally be mountable some distance away to enable easy cleaning and be suitable for a hygienic environment.

Old systems with spring-loaded wand-actuators in contact with the box were unreliable and require regular adjustment and the contact probes need frequent, time-consuming cleaning. An ultrasonic sensor-based system offers the potential to work on a fit-and-forget basis.


Contrinex ultrasonic sensors are ideal for presence and level-sensing applications, and this application uses an M30 diffuse sensor. The 20 to 130cm operating range of this metal-bodied, IP65-rated device is ideal because detection is independent of the target’s colour, shape, material or surface structure.

On detection of a contaminated box, a mechanical diverter shunts the box to a separate conveyor for manual emptying.

Product advantages

 Well proven, highly reliable detection,

 Independent of colour and texture,

 Unmatched sensing distances, 

 Choice of metal or plastic housing,

Exceptional price/performance ratio.

Click to download Contrinex’s Product Overview brochure to find out more.

Find more information about Contrinex’s sensors, please visit or call T: 0121 58 222 58.