Numerical analysis even though a powerful tool has its downsides, as you always get an approximation and not the exact answer. The error in results can be reduced to a significant amount depending upon our needs.
Here is 50 Measuring instruments for mechanical engineer. Every Mechanical Engineering student or employ should know about this.
Vernier caliper and Micrometer both are widely used in industries for daily quality control. Both are simple to use and easy for measurement.