Centimeters of Mercury – cmHg

Definition: A unit of pressure equal to the pressure exerted by a 1 cm high column of mercury at 0°C.

Conversion: 1 cmHg = 133.32 Pa (Pascals)

Applications:

• Medicine: Blood pressure measurement.
• Vacuum Technology: Lower pressure range measurement.
• Other: Less common in meteorology and automotive engineering for pressure measurement.

Related Term: Millimeters of Mercury (mmHg) – 1 cmHg = 10 mmHg

Notes:

• Declining use in favor of Pascal (SI unit).
• Temperature-dependent (assumes 0°C).
• Safety concerns with mercury use.

In essence: cmHg is a traditional pressure unit being replaced by Pascal due to temperature dependence and safety concerns.