584 



LABORATORY EXERCISES 



3. Focus the scale of each micrometer accurately and the lines in them parallel. 



4. Turn the micrometer screw until the movable line has traversed one division 

 of the stage micrometer note the number of complete revolutions (by means of the 

 recording comb) and the fractions of a revolution (by means of scale on the head 

 of the micrometer screw) which are required to measure the o.oi mm. 



5. Make several estimations and average the results. 



6. Note the optic combination employed in this experiment and record it care- 

 fully, together with the micrometer value in terms of 11. 



7. Repeat this process for each of the different optic combinations and record 

 the results. 



To measure an object by this method, simply note the number of revolutions and 

 fractions of a revolution of the screw, and eiqjiess the result as microns by reference 

 to the recorded values for that particular optic combination. 



Table of Micrometer Vahies 



' The tube length given has to be observed strictly and this tube length is 

 understood inclusive of the nosepiece. 



