Many wastewater collection system technicians have had this experience: You need to inspect a line, or set up a skid for waterjet cleaning, but from your vantage point in the street you can’t confidently tell if the pipe is 6-inch or 8-inch. And you’d rather not perform a confined-space entry to go down the manhole and use a tape measure.Trent Tobiason, a sewer maintenance worker for the City of Columbus, Neb., faced such issues often — and developed a solution. “It’s a simple device that can be built with about $10 to $15 in parts from a hardware store,” he
