A differential pressure sensor comprising: a pressure sensor, the pressure sensor comprising: a MEMS pressure transducer with a pressure sensing diaphragm and sensor elements (108, 110); an isolator diaphragm (136, 152) spaced apart from the pressure sensing diaphragm; and a header body having an electrical conductor and a transducer aperture with the MEMS pressure transducer supported therein, wherein the isolator diaphragm (136, 152) is sealably fixed to the header body and coupled to the MEMS pressure transducer by a low coefficient of thermal expansion fluid (106, 107) disposed within the aperture, the header body bounds the fluid (106, 107), wherein the header body includes a pedestal shelf bounding the transducer aperture, and further comprising a pedestal seated on the pedestal shelf, bounding the fluid (106, 107) and supporting the MEMS pressure transducer within the transducer aperture, the header body divided into a first chamber and a second chamber, wherein the isolator diaphragm (136, 152) is a first isolator diaphragm and further comprising a second isolator diaphragm, the second isolator diaphragm seated on the header body on a side of the MEMS pressure transducer opposite the first isolator diaphragm, characterized by: the electrical conductor including an exterior contact pad on an exterior surface of the header body outside the first chamber, electrically connected to an interior contact pad located inside the first chamber on the exterior surface of the header body by a via electrically connected to the exterior contact pad, a trace electrically connecting the via to the interior contact pad, the trace and via located within the ceramic header body, and a trim resistor electrically connected to the interior contact pad and spaced apart from the first isolator diaphragm; a first wire bond connecting the trim resistor to the MEMS pressure transducer; and a second wire bond connecting the interior contact pad to the trim resistor, wherein the header body is a ceramic header body, the MEMS pressure transducer is seated against the side walls of the aperture, and the electrical conductor is insulated by the ceramic header body to electrically connect the MEMS pressure transducer with the external environment. a pressure sensor, the pressure sensor comprising: a MEMS pressure transducer with a pressure sensing diaphragm and sensor elements (108, 110); an isolator diaphragm (136, 152) spaced apart from the pressure sensing diaphragm; and a header body having an electrical conductor and a transducer aperture with the MEMS pressure transducer supported therein, wherein the isolator diaphragm (136, 152) is sealably fixed to the header body and coupled to the MEMS pressure transducer by a low coefficient of thermal expansion fluid (106, 107) disposed within the aperture, the header body bounds the fluid (106, 107), wherein the header body includes a pedestal shelf bounding the transducer aperture, and further comprising a pedestal seated on the pedestal shelf, bounding the fluid (106, 107) and supporting the MEMS pressure transducer within the transducer aperture, a MEMS pressure transducer with a pressure sensing diaphragm and sensor elements (108, 110); an isolator diaphragm (136, 152) spaced apart from the pressure sensing diaphragm; and a header body having an electrical conductor and a transducer aperture with the MEMS pressure transducer supported therein, wherein the isolator diaphragm (136, 152) is sealably fixed to the header body and coupled to the MEMS pressure transducer by a low coefficient of thermal expansion fluid (106, 107) disposed within the aperture, the header body bounds the fluid (106, 107), wherein the header body includes a pedestal shelf bounding the transducer aperture, and further comprising a pedestal seated on the pedestal shelf, bounding the fluid (106, 107) and supporting the MEMS pressure transducer within the transducer aperture, the header body divided into a first chamber and a second chamber, wherein the isolator diaphragm (136, 152) is a first isolator diaphragm and further comprising a second isolator diaphragm, the second isolator diaphragm seated on the header body on a side of the MEMS pressure transducer opposite the first isolator diaphragm, the electrical conductor including an exterior contact pad on an exterior surface of the header body outside the first chamber, electrically connected to an interior contact pad located inside the first chamber on the exterior surface of the header body by a via electrically connected to the exterior contact pad, a trace electrically connecting the via to the interior contact pad, the trace and via located within the ceramic header body, and a trim resistor electrically connected to the interior contact pad and spaced apart from the first isolator diaphragm; a first wire bond connecting the trim resistor to the MEMS pressure transducer; and a second wire bond connecting the interior contact pad to the trim resistor, wherein the header body is a ceramic header body, the MEMS pressure transducer is seated against the side walls of the aperture, and the electrical conductor is insulated by the ceramic header body to electrically connect the MEMS pressure transducer with the external environment.