A process pressure measuring system includes a transmitter having a first sealed system in which a first outlet couples to a pressure sensor, a first isolator diaphragm assembly, a first capillary passage, and a first isolation fluid. The first isolation fluid couples a first pressure from the first isolator diaphragm to the first outlet and the pressure sensor. A second sealed system includes a second pressure outlet that is coupled to the first isolator diaphragm assembly, a second isolator diaphragm assembly, a second capillary passage and a second isolation fluid. The second isolation fluid is adapted for use in a first temperature range and couples a pressure from the second isolator diaphragm assembly to the second pressure outlet. A third sealed system includes a third pressure outlet that is coupled to the second isolator diaphragm assembly, a third isolator diaphragm assembly, a third capillary passage and a third isolation fluid. The third isolator fluid is adapted for use in a second temperature range and couples a process pressure to the third pressure outlet.