I am looking to monitor surface and water temperatures using a Particle Boron, Type E thermocouple wire + Adafruit MAX31856 (3.3v), and a 24vDC 4-20mA infrared sensor.
Is it possible to use the 24v sensor powered externally, grounded with resistors to the Boron? Will the 0-3.3v be compatible?
If it is possible, can the two sensors be used simultaneously? I know there is only one ground, so I am thinking that the two would need to share a ground.
There are also IR sensors that output via Type K thermocouple. Using one of those, the 24v sensor would be entirely ignorant of the Boron’s existence. Just have two thermocouple amplifiers, one reading the Type K output from the sensor and the other reading normal thermocouple water temp.
I have attached a crude wiring diagram. I am certain something here is wrong, any ideas are greatly appreciated. Thanks!