What tool is typically used to measure the clearance between piston rings and ring lands?

The tool that is typically used to measure the clearance between piston rings and ring lands is a thickness gauge. This instrument is specifically designed to measure small spaces or gaps with precision, making it highly suitable for this application. Piston rings fit into specific grooves in the piston, and a proper clearance is essential for optimal engine performance and reliability. The thickness gauge allows for the measurement of the ring's thickness against the space it occupies, ensuring that the fit is neither too tight nor too loose.

In contrast, other tools such as calipers, micrometers, and depth gauges serve different primary purposes. Calipers measure the distance between two opposite sides of an object and could be used for broader measurements but are less precise for the small gaps involved. Micrometers are excellent for measuring thickness or diameter of small components but are typically used for parts that need tight tolerances rather than clearances between components. Depth gauges are designed to measure how deep a hole or recess is, which is not applicable in measuring the clearance between the piston rings and their lands. Therefore, the thickness gauge stands out as the most suitable tool for this specific measurement task.