Using the equation for absolute vacuum pressure, what is the absolute pressure if a vacuum gauge reads 22.2 inHg and the barometric pressure is 27.68 inHg?

To calculate the absolute pressure from a vacuum gauge reading, you can use the formula:

[ \text{Absolute Pressure} = \text{Barometric Pressure} - \text{Vacuum Gauge Reading} ]

In this scenario, the vacuum gauge reads 22.2 inHg, indicating how much the pressure is below atmospheric pressure. The barometric pressure is given as 27.68 inHg, which is the atmospheric pressure at that location.

Plugging the values into the formula:

[ \text{Absolute Pressure} = 27.68 , \text{inHg} - 22.2 , \text{inHg} ]

Calculating this gives:

[ \text{Absolute Pressure} = 5.48 , \text{inHg} ]

This indicates that the absolute pressure within the system is 5.48 inHg, showing how much pressure remains above a complete vacuum. The answer reflects a critical understanding of how vacuum pressure readings relate to absolute pressure measurements, ensuring that technicians can calculate actual pressures in various systems accurately, which is vital for instrumentation and control processes.