Measurement Tools Flashcards

When using a micrometer, what does one full revolution of the thimble equal on a standard inch micrometer?

Answer: 0.025 inch

One full revolution of the thimble on a standard inch micrometer advances the spindle 0.025 inch.

Which type of square is used to check both 45-degree and 90-degree angles?

Answer: Combination square

A combination square has a sliding head that can be set to check both 45-degree and 90-degree angles.

A dial indicator reads 0.035 inch. If the needle moves 2 more full revolutions (each revolution = 0.100 inch), what is the total reading?

Answer: 0.235 inch

Two full revolutions equal 0.200 inch added to the initial 0.035 inch gives 0.235 inch.

What tool is best suited for measuring the inside diameter of a large pipe with a diameter over 6 inches?

Answer: Inside micrometer

An inside micrometer (tubular or rod type) is designed for measuring large internal diameters directly.

What is the purpose of a surface plate in precision measurement?

Answer: To provide a known flat reference surface for layout and inspection

A surface plate provides an accurate flat reference datum for layout, inspection, and measurement work.

Which instrument measures angles in degrees, minutes, and seconds with the highest precision?

Answer: Optical vernier bevel protractor

An optical vernier bevel protractor can resolve angles to 5 minutes (1/12 degree) or finer with the vernier scale.

What does 'runout' measure when using a dial indicator on a rotating shaft?

Answer: The total variation in the surface position relative to the axis of rotation

Runout is the total indicator reading (TIR) showing how much a surface deviates from true rotation about an axis.