= 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> $1000\,\mathrm{kg\,m^{-3}}$, gravitational acceleration $9.81\,\mathrm{m\,s^{-2}}$ and level difference $0.10\,\mathrm m$,
$$
\Delta p=\rho g\Delta h=981\,\mathrm{Pa}.
$$
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.<Rectoanal sensorimotor response in humans during rectal distension by Sherrie De Ocampo and others>[Methods and Results: graded distension, six sensors and multiple response components]{ref} Calibration converts a sensor signal into <pressure>; interpreting the trace additionally requires the anatomy and timing of the intervention.
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