I was looking for quick ports that can be insalled in your evaporator temp. ports and use just one thermometer. I found this company
Peterson product co 1-800-926-1926
They have a product called the PETES PLUG that screws into your 1/4 or 1/2 NPT port on the side of the evap and it is a sealed opening that you can push your temp probe into and leave it there or pull it out without liquid loss. If you want to put them in the flue pan, syrup pan,preheater, bottler and finich pans and use one thermometer you can do that.
They have a digital themometer for $75.00 and the ports are $7.00 each so you can put them all over the place. They dont make the bulk head type but you can get washers and nuts that fit pipe thread from good hardware stores and make your own fitting if you dont want to weld on your pans.