Manometry

Manometry is measurement of pressure using a manometer or a calibrated pressure-sensing system. The reference matters: gauge pressure is relative to surrounding atmospheric pressure, whereas another setup can compare two enclosed regions. In physiological measurements, the sensor position and the time course often matter as much as a single reported value.

A fluid-column manometer translates pressure difference into a height difference through hydrostatic pressure. For a stipulated water column with density $1000\mathrm{kg}{\mathrm{m}}^{-3}$, gravitational acceleration $9.81\mathrm{m}{\mathrm{s}}^{-2}$ and level difference $0.10\mathrm{m}$,This is a worked physical example, not a physiological reference range.

For an electronic physiological example, investigators placed a six-sensor probe in the anorectum and inflated a rectal balloon in 23 healthy subjects. The recorded pressure traces distinguished relaxation associated with the rectoanal inhibitory reflex from contractile responses and reported sensation.^[ref] Calibration converts a sensor signal into pressure; interpreting the trace additionally requires the anatomy and timing of the intervention.