Microscopes

Microscope: A tool used by people to enlarge microscopic objects Microscope: A tool used by people to enlarge microscopic objects Microscopic: extremely small, cannot be seen without a microscope Microscopic: extremely small, cannot be seen without a microscope

Lens- a curved transparent piece of glass that bends light, which may increase the size of the object Lens- a curved transparent piece of glass that bends light, which may increase the size of the object Simple microscope- has one lens Simple microscope- has one lens Compound microscope- has two or more lenses Compound microscope- has two or more lenses Electron microscope- uses beams of electrons to magnify objects, instead of light Electron microscope- uses beams of electrons to magnify objects, instead of light

Parts of the microscope Eyepiece (or ocular)- used to look through and helps to magnify Eyepiece (or ocular)- used to look through and helps to magnify Body tube- holds the lenses at the proper distance so the microscope can focus Body tube- holds the lenses at the proper distance so the microscope can focus Revolving nose piece- holds and allows the objective to be turned into viewing position Revolving nose piece- holds and allows the objective to be turned into viewing position

Objectives- are the lenses Objectives- are the lenses Low power is 4 times magnification. Always start and end with this lens. Low power is 4 times magnification. Always start and end with this lens. High power is 40 times magnification. It is the longest lens, never use the coarse adjustment knob with high power lens High power is 40 times magnification. It is the longest lens, never use the coarse adjustment knob with high power lens

Stage- the place that the slide is put on Stage- the place that the slide is put on Stage clip- holds the slide in place Stage clip- holds the slide in place Diaphragm- controls the amount of light that is passing through an object Diaphragm- controls the amount of light that is passing through an object Fine adjustment knob- smallest of the two knobs, used to sharpen image Fine adjustment knob- smallest of the two knobs, used to sharpen image Coarse adjustment knob- largest of the two knobs, used for a quick focus, never on high power Coarse adjustment knob- largest of the two knobs, used for a quick focus, never on high power

Arm- supports the microscope and is used to carry it Arm- supports the microscope and is used to carry it Base- supports the microscope and is used to carry it Base- supports the microscope and is used to carry it Light source- provides the light Light source- provides the light

Magnify The word magnify means “make bigger”. The word magnify means “make bigger”. The number on microscope lenses tell you how much they magnify the image of the object you are looking at. The number on microscope lenses tell you how much they magnify the image of the object you are looking at. The magnification of a lens is also referred to as its power. The magnification of a lens is also referred to as its power.

Total magnification The objective lenses have different numbers on them. The objective lenses have different numbers on them. To determine the total magnification of an objective lens and the eyepiece working together, you multiply the magnifications together. To determine the total magnification of an objective lens and the eyepiece working together, you multiply the magnifications together. Example: When you use 10x eyepiece with 4x objective lens total magnification is 40x. Example: When you use 10x eyepiece with 4x objective lens total magnification is 40x.

Using the microscope

Carry the microscope- with one hand on the base and one hand on the arm Carry the microscope- with one hand on the base and one hand on the arm Do not touch- the lens with your finger Do not touch- the lens with your finger Always focus- first with the low power objective Always focus- first with the low power objective Do not use the coarse adjustment knob to focus the high power objective lens Do not use the coarse adjustment knob to focus the high power objective lens Use only the fine adjustment knob when focusing on the high power objective lens. Use only the fine adjustment knob when focusing on the high power objective lens.

Using the microscope 1. Place the microscope on a flat surface away from the edge of the table. 1. Place the microscope on a flat surface away from the edge of the table. 2. Look through the eye piece, adjust the diaphragm for the best amount of light. 2. Look through the eye piece, adjust the diaphragm for the best amount of light. 3. Place the slide on the stage so the object is in the center. 3. Place the slide on the stage so the object is in the center. 4. Always focus first with the low power objective and the coarse adjustment knob. 4. Always focus first with the low power objective and the coarse adjustment knob.