The pressure exerted by a 760 mm column of mercury at 0 °C is known as

The pressure exerted by a 760 mm column of mercury at 0 °C is defined as 1 atmosphere (atm) [2]. This value represents the standard atmospheric pressure at sea level [4]. In SI units, 1 atmosphere is exactly equal to 101,325 pascals (Pa) [1]. Historically, atmospheric pressure was measured using a mercury barometer, where the weight of the air column is balanced by a column of mercury; at sea level, this height is approximately 760 mm or 29.92 inches [2]. While 1 bar is a similar unit of pressure (100,000 Pa), it is slightly less than 1 atmosphere (1.01325 bar) [1]. The unit 'poise' is unrelated as it measures dynamic viscosity rather than pressure. Therefore, 760 mm Hg at 0 °C specifically corresponds to the standard atmosphere unit.

Sources

1. [1] Physical Geography by PMF IAS, Manjunath Thamminidi, PMF IAS (1st ed.) > Chapter 23: Pressure Systems and Wind System > 23.1. Atmospheric Pressure > p. 304
2. [2] Certificate Physical and Human Geography , GC Leong (Oxford University press 3rd ed.) > Chapter 13: Weather > The Elements of Weather and Climate > p. 117
3. [4] https://www.sciencedirect.com/topics/engineering/standard-atmospheric-pressure