To verify a micrometer’s accuracy before precision measurements, which instrument would you use?

To verify a micrometer’s accuracy before precision measurements, which instrument would you use?

• A. Dial indicator
• B. Gauge block
• C. Caliper
• D. Depth gauge

Answer: (B)

A precise length standard is used to verify a micrometer’s accuracy. Gauge blocks are the precision length standards in metrology, manufactured and certified to extremely tight tolerances with known thicknesses. By measuring a gauge block (or a stack of blocks) with the micrometer, you compare the readout to the block’s true thickness. If the micrometer reads that known value within tolerance, you’ve confirmed its accuracy for precision measurements. This method uses a stable, true-length reference across the micrometer’s range. Other tools aren’t fixed-length standards: a dial indicator measures displacement rather than a true external dimension, a caliper is less precise, and a depth gauge measures depth rather than the external measurement the micrometer performs.

A precise length standard is used to verify a micrometer’s accuracy. Gauge blocks are the precision length standards in metrology, manufactured and certified to extremely tight tolerances with known thicknesses. By measuring a gauge block (or a stack of blocks) with the micrometer, you compare the readout to the block’s true thickness. If the micrometer reads that known value within tolerance, you’ve confirmed its accuracy for precision measurements. This method uses a stable, true-length reference across the micrometer’s range. Other tools aren’t fixed-length standards: a dial indicator measures displacement rather than a true external dimension, a caliper is less precise, and a depth gauge measures depth rather than the external measurement the micrometer performs.