Is there such a hand tool that can be attached to the end of a gas line run that can measure the amount of BTU at the END of the run? We had an outdoor gas firepit installed last fall and the burner is rated for 150,000 BTU. The plumber we hired obviously didnt calculate correctly for this. He ran a 1/2OD poly coated copper pipe from the meter to the fire pit. The run is about 60'-68 feet from the meter. We are going to replace about 48' with 1" pipe and leave the last 12' as the 1/2"OD (which is under a newly finished brick patio and fieldstone fire pit that ISN'T GETTING TORN UP). I have been told that we can probably get the total BTU up to around 110,000-130,000 depending on which plumber I have asked. Once this is done I will need to replace the firepit burner with a smaller one based on the BTU so I will need to have a pretty accurate BTU number. This is why I am looking for the total BTU. Before you chime in...Yes I did paid the first plumber, yes he is licensed, no im not using him again. At this point I need to work with what I have and make it the best I can considering the circumstances. He made a mistake and at the end of the day its not the end of the world. Just trying to make it the best I can at this point. Thank you for your time!