In what units are pressure gauges typically calibrated?

Pressure gauges are typically calibrated in units that express the force exerted over a specific area. Pounds per square inch (psi) is a standard measure of pressure that quantifies how many pounds of force are applied to each square inch of surface area. This unit is commonly used in various industries, including HVAC, automotive, and manufacturing, due to its clarity and practicality in measuring pressure levels in gases and liquids.

Other units of pressure include pascals, bars, and atmospheres, but in many North American contexts, psi is the most prevalent. The clear relationship between force and area provided by psi makes it an effective and widely accepted measure of pressure in everyday applications.

The other options do not relate directly to pressure measurements. Liters measure volume, degrees Fahrenheit measure temperature, and watt-hours measure electrical energy, making them unsuitable for describing pressure.