Elevation Corrections for Absolute-Pressure Measurements

A method of correcting absolute-air-pressure measurements for small differences in the elevations of pressure taps and pressure transducers has been devised. The variation in air pressure with elevation is well documented; nevertheless, in such disciplines as process control and laboratory experimentation, it has been common practice to account for pressure differences associated only with large differences in elevation along tubes that connect pressure taps to transducers. The emergence of highly accurate multiport pressure-measurement systems, coupled with the need for increasingly accurate pressure measurements, has made it necessary to correct for pressure differences associated with elevation differences as small as a meter or so. The present method can be readily incorporated into future pressure-measurement procedures to provide the necessary corrections; it can also be used to reprocess previous measurements to increase their accuracy.