This is simple! Your Ph probe will be linear ie: The Ph level from say 0 to 10 is directly proportional to 4 to 20mA. So... Ph 0 = 4mA, Ph 5 = 12mA & Ph 10 = 20mA. If you like I can write a simple code when I have time but do let me know how you get on.
Bye,Rabbit.
