During my brew day yesterday, I found that both my inline dial thermometers were reading low by 3ºF (calibrated with my Thermapen, which I trust) even though I had calibrated both a couple of days before (both at freezing and boiling), I'm thinking of going with an RTD type probe at least for the output of my MT since I recirculate (1/2" NPT with a 2" probe so I can just make a simple replacement). Those seem easy to find on Amazon (e.g, Akozon RTD PT100 Waterproof Temperature Sensor 1/2" NPT Threads with 2 Meter Cable: Amazon.com: Industrial & Scientific) but what should I be looking at for the device to read the output? Finding a PID controller is pretty straightforward, but I don't need the control function, just a reading (preferably in ºF) and the ability to calibrate.