A feeler gauge is used to measure which quantity?

A feeler gauge is used to measure which quantity?

• A. Electrical resistance
• B. Clearance gap on a spark plug
• C. Torque
• D. Length of bolt

Answer: (B)

Feeler gauges are used to measure small clearances by using a set of thin, calibrated blades. For a spark plug, the critical distance is the gap between the center electrode and the ground electrode. You select a blade that fits the plug gap with a light drag; the blade’s thickness gives the exact clearance. This tool is all about distance and fit, not electrical properties, so it isn’t used to check electrical resistance, torque, or overall length. Electrical resistance requires a meter, torque relies on a torque wrench, and length is measured with a ruler or caliper.

Feeler gauges are used to measure small clearances by using a set of thin, calibrated blades. For a spark plug, the critical distance is the gap between the center electrode and the ground electrode. You select a blade that fits the plug gap with a light drag; the blade’s thickness gives the exact clearance. This tool is all about distance and fit, not electrical properties, so it isn’t used to check electrical resistance, torque, or overall length. Electrical resistance requires a meter, torque relies on a torque wrench, and length is measured with a ruler or caliper.