What is the inch of mercury?
Q: What is the inch of mercury?
A: The inch of mercury (inHg or "Hg) is a non-SI unit of pressure used for measuring barometric pressure, (the thickness of air), in weather forecasts and aviation (flying).
Q: How was it replaced?
A: It was replaced by the pascal.
Q: What does it measure?
A: It measures the amount of pressure that a column of mercury that is one inch tall has at 0 °C at the standard acceleration of gravity.
Q: What else does it measure?
A: It also measures how fast things speed up as they are falling because of gravity.
Q: Is this unit still in use today?
A: No, this unit has been replaced by the pascal and is no longer in use today.
Q: Where was this unit used before being replaced?
A: This unit was used for measuring barometric pressure, (the thickness of air), in weather forecasts and aviation (flying).
Q: Why did it need to be replaced?
A: It needed to be replaced because it was not an SI unit and therefore could not accurately measure certain pressures.
