The DF702 uses an ultrasonic radar not dissimilar to a car reverse sensor and is used to measure distances from 15cm to 200cm with an accuracy of 3mm. It also sensors flame risk and inclined (fall) information.
Demonstration Project
To demonstrate this sensor, we choose a public park bin in the City of Port Adelaide Enfield catchment in partnership with our Waste and Recycling Department. The sensor was located on an existing bin in the park’s centre.
For the DF702 Sensor to measure the contents of a waste bin, the sensor must be positioned above the bin, looking down into the waste area. However, it must also be mounted so as not to obstruct the opening allowing the public to put their rubbish into it easily. Also, as the bin contents are accessed through a lid on the top, anything attached must allow the lid to be opened and allow the internal bin to be removed and emptied without getting damaged. This type of sensor also uses radio signals, so it cannot be put inside the bin enclosure as the metal casing blocks the signal. However, even if this were not a problem, mounting this type of sensor inside the bin would obstruct the flow of rubbish.
A bracket was made using a 3mm galvanized steel plate for strength and then coated to reduce rust over time. All sharp edges were removed and attached using tamper-proof stainless security screws to increase the difficulty of removing it without the correct security tool. A rubber mount was also added to reduce vibration and allow some give in cases of accidental collision from passing bikes, trollies or prams.
