cmH2O (Centimeters of Water)

cmH2O measures pressure as the height of a water column that exerts equal pressure. (1 cmH2O = pressure exerted by a 1 cm high water column at 4°C).

Common Use: Despite not being SI (Système International), cmH2O remains common in:

• Medicine: Blood pressure measurement (often converted to mmHg).
• Building Services: Assessing pressure in plumbing and HVAC systems.
• Industry: Testing pressure in various equipment.

Note:

• cmH2O measures pressure, not force.
• Temperature can affect readings slightly due to water density changes.
• For high pressure, Pascals (Pa) are preferred (SI unit).