Which tool is used to calibrate a micrometer for accuracy?

A gage block is the appropriate tool used to calibrate a micrometer for accuracy. Gage blocks are precision blocks made from high-quality materials that have a very accurate dimension. When calibrating a micrometer, the gage block can be used to set a known distance against which the micrometer can be measured. By adjusting the micrometer until it reads the same as the gage block, the user ensures that the micrometer is providing an accurate measurement, which is essential for achieving precise results in manufacturing and measurement tasks.

Using a calibration ruler may not provide the same level of precision required for micrometer calibration, as calibration rulers usually have less stringent accuracy specifications and may not be designed specifically for the same level of precision as gage blocks. A depth gauge, while useful for measuring depths, is not typically used in the calibration of micrometers. Similarly, a laser measuring tool can offer highly accurate measurements but is not the standard or most practical choice for the specific purpose of calibrating a micrometer. Gage blocks remain the preferred choice because they are specifically designed for this purpose and are widely accepted in precision measurement practices.