In this video, I test out a cheapie portable gas leak detector to see if it works. It did a pretty decent job on a small LP gas leak and also could detect butane.
I'll add it to my existing RV gas leak detection tools - an electronic manometer, a good old soapy solution, and Anne's super sniffer. Never can be too safe when it comes to propane leaks aboard the RV.
I've had a "SGILE Gas Detector" for several years and use it quite often. I like the flexible detector for getting into tight places. I did have an occasion where I found a very small leak with bubbles and seemingly this would not detect it. On Amazon it was $30 and is no longer available.