A pressure gauge mounted at the bottom of an open tank of water indicates 17 psig. What is the level of water in the tank?

To determine the level of water in the tank based on a pressure gauge reading of 17 psig, it's important to understand the relationship between pressure, fluid density, and height of the fluid column.

Pressure gauges measure the pressure exerted by the fluid above the gauge, plus atmospheric pressure. Since the gauge reads 17 psig, this means the pressure is 17 pounds per square inch above atmospheric pressure. To find the difference in height of the water in the tank, you can use the formula:

[ P = \rho g h ]

Where:

• ( P ) is the pressure in pounds per square inch (in this case, 17 psi).
• ( \rho ) is the density of the fluid (for water, approximately 62.4 lb/ft³).
• ( g ) is the acceleration due to gravity (commonly taken as 32.2 ft/s² when converting to lb).
• ( h ) is the height of the fluid column in feet.

First, you need to convert psi to feet of water. The conversion factor is approximately 0.433 psi per foot of water. Thus, the height (h) of the water can be calculated as follows:

[ h = \