PARA LAB: MICROMETRY

• Micrometry is a technique used to measure the size of microscopic objects
• Principle of Micrometry involves the calibration of the ocular micrometer using the stage micrometer
• Ocular micrometer is a glass disc with 100 equal divisions or lines, placed in the ocular of the microscope with no absolute value
• Stage micrometer is used to calibrate the ocular micrometer, it looks like a microscope slide with a standard scale etched into it
• The smallest divisions on the stage micrometer are 0.01 mm in length, which is equal to 10 micrometers (um)
• 10x ocular lens with ruler magnifies the image 10 more times, while the 4x objective lens magnifies the image 4 times, resulting in a total magnification of 40x for the specimen
• 1 division marker on the ocular ruler represents 0.1 millimeters (mm) or 10 micrometers (um)
• Objective Lens calibration:

  • 4x objective lens corresponds to a length of 25 micrometers (um)
  • 10x objective lens corresponds to a length of 10 micrometers (um)
  • 40x objective lens corresponds to a length of 2.5 micrometers (um)