Make a formula(or analysis) containing variables from 2 different devices

Make a formula(or analysis) containing variables from 2 different devices

Hello !
I am wondering if there is a way to make a formula (or analysis) that can take in variables from 2 different devices.
I have one device monitoring the pressure in the air and one the pressure in water.
And i would like to take the one minus the other, times another value and get the result in a graph. is that possible ?
if so, how ? :)