Which tool is essential for ensuring proper tire pressure during inspections?

The pressure gauge is the essential tool for ensuring proper tire pressure during inspections because it is specifically designed to measure the amount of air pressure inside a tire. Maintaining the correct tire pressure is crucial for safe vehicle operation, as it affects handling, fuel efficiency, and tire wear. A pressure gauge allows the operator to accurately assess whether the tire pressure is within the manufacturer's recommended specifications. This tool provides immediate feedback, making it easier to identify under-inflation or over-inflation issues that could compromise vehicle safety and performance.

Other tools, while useful for different maintenance tasks, do not provide the ability to directly measure tire pressure. A wrench is typically used to tighten or loosen bolts, a jack is used to lift the vehicle for tire changes or inspections, and a caliper helps measure the thickness of brake pads or other components, but none of these have the capability to assess tire pressure.