RF remotes generally work this way: The originating signal is sent from the remote as RF (radio frequency.) In the case of the MX-950 in my theater that's 418MHz, a very stable and reliable frequency band.
By nature, propane is clear and contains no scent at all. For safety purposes propane. companies add a substance known as ethyl-mercaptan to the propane fuel. Ethyl-. mercaptan has a strong rotten egg, or skunk-like scent, which allows the consumer to. smell it in the case of a leak.
Propane is a hydrocarbon and is sometimes referred to as liquefied petroleum gas, LP-gas, or LPG. Nearly 97% of propane consumed in the United States is produced in North America. It is non-toxic, colorless, and virtually odorless. As with natural gas, an identifying odor is added so the gas can be readily detected.