METHOD AND APPARATUS FOR CAPACITANCE TEMPERATURE COMPENSATION AND USING THEM IN A DUAL PLATE CAPACITIVE PRESSURE - TRANSMITTER

• Main Authors: SEEMAN,BRIAN, SCHULTE,JOHN P, LOFGREN,LYLE E
• Format: Patent
• Language: English
• Published: 29.05.1995
• Edition: 5
• Subjects: ARRANGEMENTS FOR MEASURING TWO OR MORE VARIABLES NOT COVEREDIN A SINGLE OTHER SUBCLASS; MEASURING; MEASURING ELECTRIC VARIABLES; MEASURING FORCE, STRESS, TORQUE, WORK, MECHANICAL POWER,MECHANICAL EFFICIENCY, OR FLUID PRESSURE; MEASURING MAGNETIC VARIABLES; MEASURING NOT SPECIALLY ADAPTED FOR A SPECIFIC VARIABLE; MEASURING OR TESTING NOT OTHERWISE PROVIDED FOR; PHYSICS; TARIFF METERING APPARATUS; TESTING

A two wire transmitter responsive to a pressure differential sensor includes a fixed module and a removable module. The fixed module is adapted for connection to an analog removable module having a compensation capacitance MACDA or a digital removable module having compensation capacitance CDD. Capacitance compensation circuitry is included in the fixed module which includes a compensation capacitance CDM which is selected whereby MACDA equals CDD when the analog removable module and the digital removable module are calibrated. This provides a pressure transfer function which is more linearized and less susceptible to temperature variations.