Which factor does not affect psi readings in hydraulic systems?

The correct choice indicates that tank shape does not impact psi readings in hydraulic systems. Psi, or pounds per square inch, is a measure of pressure in fluid systems. Pressure in a hydraulic system is primarily determined by the height of the fluid column above the measuring point (fluid height), the density of the fluid, and temperature, all of which influence how much pressure is exerted at a given depth.

Fluid height directly correlates with pressure because, as the height of the fluid column increases, so does the pressure at the base due to the weight of the overlying fluid. Fluid density is also a crucial factor since denser fluids exert more pressure than less dense fluids at the same height. Additionally, fluid temperature can affect density and viscosity, thereby influencing pressure measurements.

In contrast, the shape of the tank—whether it is cylindrical, rectangular, or any other design—does not change the fundamental relationship between fluid height, density, and pressure. Therefore, it does not affect psi readings directly, making it the correct answer in this context.