Erma Ocular Micrometer
Ocular Micrometer is a device used to measure the size of magnified objects under a microscope. An ocular micrometer is calibrated by comparing it with a calibrated stage micrometer.
Scale: 10 mm
Least Count: 0.1mm
Dimensions: Ø 19mm x 1.5 mm
Instructions to calibrate an Ocular Micrometer
1. Insert the ocular micrometer into a 10X eyepiece. The ocular micrometer is divided into ocular divisions(OD).
2. Place the calibrated stage micrometer slide on the stage and focus on the scale. The stage micrometer has a calibrated scale which is divided into 0.1 millimeters (mm) and 0.01 mm units.
3. Adjust the field so the 0 line of the ocular micrometer (OM-010) scale is exactly superimposed upon the 0.0 line of the stage micrometer (SM-001)scale.
4. Without moving the stage micrometer, locate the point as far to the extreme right as possible where any two lines are exactly superimposed upon each other.
5. Count the number of divisions (mm) on the stage micrometer between the 0.0 line and the superimposed line to the far right.
6. Count the number of ocular divisions on the ocular micrometer between the 0 line and the superimposed line to the far right.
7. Divide the distance determined in step 5 by the number of ocular divisions in step 6 and multiply by 1000 to give the ocular micrometer units in µm.
8. Repeat steps 3 through 7 for each objective on the microscope.
9. If at any time the ocular micrometer is moved to a different microscope or a new objective is added to the microscope, the calibration procedure must be completed again.
