Editing Depth gauge (section)

=== Membrane depth gauge ===
{{main|Pressure measurement#Membrane}}

In a membrane depth gauge, the water presses onto a metal canister with a flexible end, which is deflected proportionally to external pressure. Deflection of the [[Diaphragm (mechanical device)|membrane]] is amplified by a lever and gear mechanism and transferred to an indicator pointer like in an [[aneroid barometer]]. The pointer may push a trailing pointer which does not return by itself, and indicates the maximum. This type of gauge can be quite accurate when corrected for temperature variations.

[[Strain gauge]]s may be used to convert the pressure on a membrane to electrical resistance, which can be converted to an analog signal by a [[Wheatstone bridge]] This signal can be processed to provide a signal proportional to pressure, which may be digitised for further processing and display.