![Razz :P](./images/smilies/icon_razz.gif)
Below is one chunk I call The Blockage Sensor.
It samples the flow of product on a belt and if it detects a blockage outputs a circuit signal via a smart chest.
If the blockage is removed then the circuit signal is cleared.
This is useful in my smeltery because if both lanes of product on the belt are blocked then a series of smart inserters dump the product into storage banks thus unblocking the belt and allowing the smelters to work on all available ore non-stop.