Abstract
Thermal gradients in pressure transducers and transmitters often cause the output to deviate from the calibrated accuracy and persist until the temperature gradient across the device diminishes. Thermal gradients can be caused by gas pockets in the well, wireline activities, well testing, and injection events, among other common activities. Rosemount Specialty Products (Paine) has implemented a sensor technology that exhibits extremely low thermal transient error in comparison to the industry leading technologies. The sensor is comprised of a single crystal that incorporates a sensitive to pressure capacitor and a reference capacitor. The material of the sensor is insensitive to temperature effects and the direct thermal coupling of the reference allows for faster correction of any remaining errors. Packaging and electronics schemes have been developed for 175°C operation and testing. The electronics were designed to reduce added thermal error, using self-calibrating gain and offset techniques, as well as incorporating an onboard microcontroller to correct residual changes in the output from temperature. Opportunities exist for future development of higher temperatures electronics, as the sensor is capable of more than 300°C. Novel packaging methods were developed to prevent additional errors caused by stress gradients, outgassing, thermoelectric, decomposition, and migration effects. This paper covers thermal transient testing against both a quartz crystal based sensor and a strain based sensor. Paine's new sensor technology exhibits less thermal error, while maintaining accuracy and stability capability similar to industry standards. A new product, 420-22-0010, is slated to be released this year based on this newly developed technology.
