Which energy efficient PLC to choose for an automated system?

Question

Automation

I had the following task in my studies: It is
necessary to design an automated temperature measurement system in the steam pipeline, the measurements obtained must be sent via a GPRS modem to the station.
The question is to choose a controller and a modem that consume little energy, connect well with each other and, preferably, have protection against temperature (up to 60-80 degrees) and humidity (90%)
Perhaps you know such a low-power PLC that you can hang up the thermocouple.
Thank you for reading this)

Answer 1

if you have 60-80 degrees in the box with electronics, and even more so high humidity, I have bad news for you , the
need for low consumption is also not justified,
but take an arduino and some sim800 examples on the internet in bulk