To speed up an end-of-line packaging station, a manufacturer wanted a simple and affordable measurement system to establish the height of incoming boxes. It turned to Contrinex.
(See PLUS Automation at FoodManufacturing.Live, 15 October 2025, on stand 49)
Contrinex's MGI Measurement Light Grids from PLUS Automation combine performance, affordability and simplicity, which makes them simple to install. The infrared light grids offer fast response times and reliable detection of varied objects with robust immunity to interference from ambient light.
Fast, simple and low-cost implementation is assured because the sensor provides a 0 to 10V or 4 to 20mA analogue output, like a conventional analogue sensor. There is no data stream to analyse, removing the need for expensive and complex processing. Set-up, therefore, can take less than 90 seconds, connecting an industry-standard 4-pin M12 cable between the transmitter and the receiver, and setting two switches.
In this particular application, to utilise existing end-of-line carton taping and wrapping machines, a solution was sought to establish the height of the incoming box and thus configure the conveyor feed speed to maximise throughout to optimise productivity.
A simple control system was designed to take the analogue 4 to 20mA signal from the Contrinex MGI measurement light grid, establishing the incoming box's height accurate to 5mm. A PLC compares the height value to a look-up table and adjusts the conveyor line speed accordingly. The PLC also presets the start height position of the wrapping machine. This removes the time delay of a measurement and positioning activity being taken within the shrink-wrapper so that the wrapping machine is now configured before the carton reaches it.
The sensor's small cross-section of only 40 x 20.5mm and rugged one-piece aluminium extruded cases make them easy to fit within existing systems. Their ability to cover a 4m distance and their immunity to interference from ambient light provides reliable measurement.
The MGI sensors are available with measurement heights up to 960mm at a 5mm resolution or 1438mm at a 12mm resolution. The sensor's response time ranges from 3 ms to 14 ms depending upon the number of beams in the unit, and pricing that ranges from 1,100 to 3,000 makes them affordable and so ideal for a wide variety of measurement applications and industries.