Hi John B
OK let’s surmise, Sensors, DCS, PLC, Logic Solvers, Final Elements etc I am well up to speed with ... on Wired System be it a HART Multiplexer or a Foundation Fieldbus H1 it is the Internet Gateways and stuff, which I can’t see ,where my knowledge is lacking haha nearly a Dinosaur but not quite just yet.
Cav
Think about Q1 T/C would be too complicated because CJC (Cold Junction Compensation) would be required, PT100 Platinum RTD would drive the cost up so my guess is a Thermistor since as you ask in Q4 the measurement range -/+10 would cover Fridges and Freezers
As for Q5 IP53 would suffice if the TX located in the cooled compartment, if outside IP32
IP53 solid bodies >1mm / Water Droplets
IP32 solid bodies > 12 mm (Fingers) / Condensation