Axioskop 2 plus OPERATIONAxioskop 2 mot plus Quantitative microscopy Carl ZeissB 40-075 e 02/01 3-51After exchange of the stage micrometer for thespecimen to be measured, the measuring distanceof interest results from the number of incrementsof the crossline micrometer (tenth estimated),multiplied by the scale value k’. Example:L = 35.5 x 9.9 μm = 351.5 μmParticularly large object structures can also bedetermined by using the vernier scale gradations(0.1 mm) on the mechanical stage. Here, it mightbe necessary to determine the distance to bemeasured through calculation from a combined xand y measurement (Pythagoras).3.7.2 Height measurementHeight measurements using the microscope are always possible to be performed if both the lower andupper side of the specimen can be focused. This should preferably be performed using a precision(Harmonic-Drive-) focusing drive and a high-aperture objective with a low depth of focus.The difference in the stage height results in a height value for transmitted-light specimens which isfalsified by the refractive index of the specimen (through which focusing was made) and perhaps by theimmersion oil. The correct height value d of the specimen measured in transmitted light results from thedifference in the stage height (focus difference) d’ and the refractive indices nP of the specimen and n Mof the medium between cover slip and specimen:d = d’ xFig. 3-32 Length measurement using scale 1on the stage micrometer (object)and scale 2 on the crosslinemicrometer (eyepiece)n Pn M1 2
