Patent attributes
A measuring device for detecting and indicating changes in fluid pressure of a test environment relative to ambient fluid conditions, wherein the measuring device includes a linear gear rack having an alignment spur, an indicator needle associated pinion gear, calibrated indicia for visual measure of a pressure change event, and a deflectable diaphragm element. The alignment spur acts upon the pinion gear by maintaining close relationship of the linear gear rack and the needle associated pinion gear and counteracts torque and off-center forces created by the linear rack gear upon deflection of the deflectable diaphragm, thus providing improved resolution of small pressure changes and increased accuracy of measurement as the measuring device operates through a cycling period.