Aprilaire humidistat sensor extention for lined ducts

After installing my Aprilaire 800 and the Aprilaire humidistat 62 that came with it, I found that the sensor on the back of the humidistat did't get far enough into the duct to get through the duct insulation and into the air stream. This lead to the humidistat never getting the correct humidity, in my case the house was at 30% RH and the # 62 displayed between 57% and 66% RH. Not wanting to drill yet another hole in my return air plenum, I made this extention for the sensor. In theory it should