Regarding the range of the transmitters, Requested range cant be changed later to higher range for example OPTIBAR 3050 with range 0....10 bar cant work with 100 mbar or 30 bar.
The ordered transmitter cannot be adjusted to 0…30bar, as the measuring cell is limited to 10bar.
If you need 0…30bar you have to go via a new transmitter, coming along with a 0…40bar measuring cell (with custom measuring range of 0…30bar).
Furthermore it is not a good idea to run the actual transmitter at 0..100mbar, as the turn-down will be way much too high (10bar = 10.000mbar / 100mbar = 1:100).
For such low measuring ranges please use a transmitter either with 400mbar or 100mbar measuring cell, in order to keep the turn-down as low as possible (high turn-down will cause negative impact on the accuracy).