Although we opted for two 80 litre holding tanks its very hard to judge how full they are. The solution is to fit some sort of gauge. Black water tanks have two types of gauge available, internal gauges that require a whole to be drilled (metal tanks can only have this type) or external sensors that stick to the tank. As our tanks are plastic we opted for the ‘stick on’ technology and selected the SCAD product from marine.com
Kit contains everything you need except addition wire and fuse for the power. The instructions are clear and it is handy to have some sort of alcohol based cleaner, we used isopropyl spray.
Start by cleaning the tank and marking where the two self adhesive strips are to be mounted, they need to be 3-4 inches apart and ½ inch gap at the top and bottom of the tank. Stick the foil on, then clean the foil where the SCAD connectors will go, again they are self adhesive.
Next bit is fun, cut a hole and mount the display unit. Any time we are putting a hole in anything we measure multiple times !! Find a suitable permanent power source and ensure you have the unit suitably fused, connect and your nearly done.
Last part, follow the instructions for tank shape and calibrate, in all took us an evening to do this.