Vernier Calipers
We were shown how to use and what a vernier caliper is today. It is basically another instrument that can be used to measure the internal and external diameter. This instrument is able to measure up to an accuracy of 0.01cm or 0.1mm. Reading this instrument is no easy task but after a few tries, i managed to master it. The method of reading are as follows:
1. Close the jaws and ensure that the zeros are present on both the vernier and main scale to form a straight line.
2. Jaws are then adjusted and clamped onto the object to be measured.
3. Note the reading on the main scale and the vernier scale.
4. Final reading=main scale reading + vernier scale reading
However, this is not the end yet because when the vernier caliper is shut, there may be a ZERO ERROR. This error may be a positive zero error or a negative zero error.
POSITIVE ZERO ERROR
The zero mark of the scale lies on the right side of the main scale when the caliper is shut so the reading will be: Actual reading =initial reading-zero error
NEGATIVE ZERO ERROR
The zero mark of the scale lies on the left side of the main scale when the caliper is shut so the reading will be: Actual reading=initial reading+zero error
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