Digital caliper: outside diameter of turned shaft Ø25

What happens in the video

1. 0:00 Digital caliper: outside diameter of turned shaft Ø25
2. 0:04 Close the jaws fully and press ORIGIN: the display reads 0.00.
3. 0:09 Open the jaws and set turned shaft Ø25 deep between them, square to its axis.
4. 0:13 Close the moving jaw gently until both faces touch.
5. 0:18 Read while the caliper is still on the part: 24.98 mm, within 24.95–25.00 mm.

In the course

• Tolerances, limit gauges and pass or fail · General tolerances — Find the tolerance of a dimension that has none written next to it.
• Measurement data, uncertainty and decisions · An uncertainty budget for a caliper reading — Build a simple uncertainty budget for a caliper measurement.

Read the guide

• 
  Tolerances and decisionsGeneral tolerances for untoleranced sizesA size with no tolerance next to it takes the general tolerance named on the drawing, for example “GB/T 1804-m”.
• 
  Tolerances and decisionsRepeated measurements: mean and standard deviationTake the mean of n repeated readings as the result.
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  Tolerances and decisionsAn uncertainty budget for a caliper measurementAn uncertainty budget lists every source of uncertainty, turns each into a standard uncertainty, combines them as the square root of the sum of squares and multiplies by a coverage factor.
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  Teaching and certificationMeasuring skills for certification and contestsPractical assessments mark not only the size of your part but how you measure it: check the instrument, clean and zero it, use the right technique for each feature, read to the resolution, record, judge against the tolerance and put the instrument away properly.