I would like to install two of these thermometers into the inlet/outlet piping of my heat pump. It appears that the tip of thermometer gets pushed through the nylon insert and sits into the plastic well. The long end of the thermometer is round and the hole in the nylon nut is square and requires some force to seat it. By doing so, there is no direct water contact on the thermometer tip. Is this designed that way so the heat transfer from the plastic tube is enough to give an accurate reading on the thermometer?