Wireless Sensor Enabling Self Calibration and Condition Based Maintenance

This SBIR proposal is for development of a ruggedized pressure sensor having capability to monitor its' own health, recalibrate if necessary, and wirelessly report its' status along with measured values. The proposed sensor substantially reduces the need for re-calibration by employing aerospace-proven silicon MEMS technology and digital compensation circuitry. Ongoing comparisons of redundant sensors will provide diagnostic information on hard failures and identify soft failures requiring calibration. Self calibration is accomplished without requiring service interruption to operate isolation valves by employing a simple, cost-effective Simulated Pressure Generator (SPG). For slope calibration, a short duration positive pressure pulse is applied to determine sensor sensitivity. For null calibration, the SPG provides a negative pressure pulse which, coupled with composite sensor technology, allows the sensing element to be momentarily decoupled from the applied pressure. An algorithm will be applied to self calibrate both slope and null offset. Initial analysis confirms that a battery pack can be designed to provide standalone power for a period of two years. Phase I deliverables include prototype test results demonstrating feasibility of SPG and battery pack functionality; component and wireless design; plans for fabrication and procurement of key components; and a technology development roadmap with Phase II/III milestones.