Natural gas sniffer truck. And, for the record, yes, yet again, "natural" is a red flag here, because natural gas is mostly methane, which is a perfectly good gas. Truck is still cool.
https://s3-us-west-1.amazonaws.com/h...fing_truck.jpg
More: Natural gas sniffer trucks
Previously:
https://www.homemadetools.net/forum/...616#post102044
https://www.homemadetools.net/forum/...479#post117039
https://www.homemadetools.net/forum/...568#post117613
https://www.homemadetools.net/forum/...048#post129912
