The following mechanical measuring instruments are explained with theory and images. Linear Measurements (Non precision instruments) -Steel Rule -Calipers -Inside caliper -Outside caliper -Spring caliper -Hermaphrodite caliper -Transfer caliper -Dividers -Telescopic gauge -Depth gauge Linear Measurements (Precision instruments) -Micrometer -External micrometer -Inside micrometer -Vernier micrometer -Screw thread micrometer -Depth micrometer -Vernier caliper -Vernier height gauge -Slip gauges -Comparators -Mechanical Comparator -Mechanical-Optical Comparator -Electrical Comparators -Pneumatic Comparator Angular Measurements (Non precision instruments) -Protractors -Bevel gauge -Engineers square -Combination set Angular Measurements (Precision instruments) -Bevel protractor -Dividing head -Sine bar -Spirit level -Clinometers -Autocollimator -Taper measurements Surface Measurements -Straightedge -Surface plate and surface gauge -Optical flat -Profilometer -Profilograph -Use of laser