Centech 93233 User manual

Junior Microscope KitJunior Microscope Kit
Junior Microscope KitJunior Microscope Kit
Junior Microscope Kit
ASSEMBLY AND OPERATING INSTRUCTIONS
3491 Mission Oaks Blvd., Camarillo, CA 93011
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Copyright © 2005 by Harbor Freight Tools®. All rights reserved. No portion of this
manual or any artwork contained herein may be reproduced in any shape or form
without the express written consent of Harbor FreightTools.
For technical questions and replacement parts, please call 1-800-444-3353
93233
Due to continuing improvements, actual product may differ slightly from the
product described herein.

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Specifications
* Close supervision by a responsible adult is required.
Applications
This instrument may be assembled in 9 different configurations, including Magnifiers,
Telescopesand Microscopes.Eachconfigurationoffersdifferentopticspecifications.
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SKU 93233 For technical questions please call 1-800-444-3353 Page 3
Save This Manual
You will need the manual for the safety warnings and precautions, assembly
instructions,operatingand maintenance procedures, partslist and diagram. Keep
your invoice with this manual. Write the invoice number on the inside of the front
cover. Keep the manual and invoice in a safe and dry place for future reference.
Safety Warnings and Precautions
WARNING:When using this device,basic safety precautions should always be
followed to reduce the risk of personal injury and damage to equipment.
Read all instructions before using this instrument!
1. WARNING! Do not look at the Sun or other strong light sources through
this instrument. Injury to eyes, even blindness may result. Do not use
this instrument to look at a Solar eclipse.
2. Observe work area conditions. Do not use tools or instruments in damp or
wet locations. Don’t expose to rain.
3. Store idle equipment. When not in use, tools and instruments must be
stored in a dry location to inhibit rust. They should be put away properly to
preventlossof small parts ordamage.
4. Maintain instruments with care. Keep tools and instruments maintained
andcleanforbetterand safer performance. The various parts mustbekept
clean, dry, and free from oil and grease at all times.When cleaning lenses
useonlycleanlens paper and an approvedlenscleaner.
5. Stay alert. Watch what you are doing and use common sense. Do not walk
or run with the instrument held to your eye. Do not look at bright lights through
theinstrument.
6. Check for damaged parts. Before using any tool or instrument, any part
that appears damaged should be carefully checked to determine that it will
operateproperlyandperformitsintendedfunction.Checkforalignmentand
bindingofmoving parts; any brokenpartsor mounting fixtures; andanyother
conditionthat may affect proper operation. Any part that is damaged should
beproperlyrepairedorreplacedbyaqualified technician.
7. Replacement parts and accessories. When servicing, use only identical
replacementparts.Useof anyother partswill voidthe warranty.Approved
accessories are availablefrom Harbor FreightTools.

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Warning:The warnings,cautions,and instructions discussed in thisinstruction
manual cannot cover all possible conditions and situations that may occur. It
mustbe understood bythe operatorthatcommon senseand caution arefactors
which cannot be built into this product, but must be supplied by the operator.
Unpacking
When unpacking, check to make sure that all accessories listed below are
included, and that the product is intact and undamaged.
If any parts are missing or broken, please call Harbor FreightTools at the number
onthe cover of thismanual.
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AboutTelescopesand Microscopes
For thousands of years mankind has sought ways of looking farther to see
distant objects, or looking closer to better see small objects.
Phoenicianscooking on sand discovered glass around 3500 BCE, but it
took about 5,000 years more for glass to be shaped into a lens for the first tele-
scope.Aspectaclemaker named Hans Lippershey (c1570-c1619) ofHolland
looked at a church steeple through two lenses placed one in front of the other and
saw thatthe imagewas magnified. Lippersheyis oftencredited with theinventionof
the telescope, but he almost certainly was not the first to make one.
The telescope was introduced to astronomy in 1609 by the great Italian
scientist Galileo Galilei, who became the first man to see the craters of the moon,
and who went on to discover sunspots, the four large moons of Jupiter, and the
rings of Saturn.Galileo’s telescope had limited magnification and a narrow field of
view.Galileo could see no more than a quarter of the moon’s face without
repositioninghistelescope.
Later, better telescopes using mirrors and various combinations of lenses
havebeendeveloped.
Refracting telescopes use
lenses to gather and bend light making
things seem larger.The lenses used in
refractingtelescopes are called
concaveand convex. Convex (curved
outward)lensesbend light inward,
makingthings bigger,but blurry.
Concave(curvedinward)lenses bend
lightoutward, making things appear
small. A combination of these two
lenses can be used to adjust the
apparent size of objects, and make
them appear in focus.
This set contains lenses of different combinations of concave and convex
lenses. Some are individual lenses, and some are combinations of lenses
cementedtogether.
As you build and experiment with the various combinations of lenses,
think about how each one magnifies or reduces, bends or redirects light.
All lenses have an “Angle of View” which is a measure of the angle the
light is bent by the lens. This is also known as a “Focal Length” which is the
distance from the lens that the light bent by the lens comes back together in
focus.The Body, Drawtube, Eyepieces and Spacers included in this kit allow you
to adjust for the Focal Length of any combination of lenses.
convexlens concave lens

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Understanding the various parts in your kit
Beforeassemblinganyopticaldevice,please read the instructions. The various
componentswork together in differentwaysto produce a specificinstrument. After
you understand how each of these parts works, you may experiment to find new
ways to put them together.
Objective Lens #8 is a magnifying lens. It is made of two lenses cemented
together.A lens which is convex on both sides has a lens which is flat on one side
andconcave on the otherattached to it. Thesmaller flat/concave lens helps
sharpentheimageseenthrough the double convex lens. WhenusingObjective
Lens#8, the flat side isalways pointed toward the objectbeing observed. The
rounded,convexsideis pointed toward the eyepiece.
Collecting Lens #4 is a combination of three lenses cemented together.A flat/
concave lens is nearest the objective. It is mounted onto a convex/flat lens which
has a flat/flat lens mounted on the inside nearest the eyepiece. Thislenshelpsalign
theimageintheimageplane,thatmeanstheimageappearsflatinfrontoftheeye.
Inversion Lenses #5 are used to turn the image right side up. A curious effect of
convex lenses like #8 is that, in addition to enlarging the image, they flip them top
tobottom. Inversion lenses areused in “terrestrial” telescopes,which are used on
land. Without an inversion lens it might be confusing to see a bird on a branch
upsidedown.Inversionlenses are often not used in“astronomical”telescopes,
since stars and planets usually look about the same whether they are upside down
ornot.Inversions in astronomical telescopesare confusing only when lookingat
familiar objects like the moon. For that reason, some astronomical telescopes
includeinversionlenses.
Eyepiece #6 is called a “diversion” lens because it bends light outward. It is a
concave lens that is used in combination with a convex magnifying lens like # 8.
Convexlensesbendlightinward,andconcavelenses bend light outward. When
usedtogether at the properfocal length, they producea magnified image withthe
light in alignment again. This is the simple design that Gallileo used, and is the
basicrefracting telescope illustrated onpage 5.
Eyepiece #7 is a “symmetric” combination of lenses. This consists of two sets of
opposite design lenses mounted in opposition to each other.The effect of this lens
is to magnify the image without distortion.
The Body, Drawtube, Eyepieces and Spacers are all provided to adjust the focal
length of any instrument you assemble from this kit. It is necessary to adjust the
focal length to result in an image in the eyepiece which is in focus.
A note on magnification. Magnification is produced by the interaction of lenses of
various sizes and shapes positioned in a certain relation to each other.It is the
perceptionofan image being largerthanit appears in nature. Magnificationis
describedas being so many times (“X”) its appearance with the unaided eye.

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#1 Galilean HandTelescope
The brilliant 17th century scientist Galileo Gallei designed this telescope
and first recorded using it in 1609. In addition to his many experiments with gravity
and various machines, Galileo wanted to determine if the Earth revolved around
the Sun, or the Sun revolved around the Earth.The answer to this question was not
known in his day.His predecessor, Copernicus, had made mathematical
observations to show that the solar system is “heliocentric”, with the Sun at the
center.But he could not
proveit. Others claimed
that the solar system is
“terracentric”withthe
Earth at the center.While
not accepted at the time,
Galileo was the first
Western scientist to prove
throughobservationwitha
telescope like this one
that the solar system is
heliocentric.
This sort of telescope has the advantage of allowing in a lot of light, so it
can be used in dark conditions. Its disadvantage is that its field of view and
magnification are very small.
To assemble a Galilean Hand Telescope:
1. Place the Body (01) on a clean, flat work surface.
2. FittheObjectiveLens(08)into the opening near the decorative covering of the
Body (01). Be sure the flat part of the Objective Lens is facing out.
3. Press the Objective Lens (08) into the Body (01) using the Rod (16) until the
mark on the Rod aligns with the outer edge of the Body.
4. RemovetheRodand set it aside.Insert the Diversion LensEyepiece (06) into
the other end of the Body (01).
5. To focus this telescope, move the Eyepiece (06) slowly in and out.
6. If it is not possible to focus the telescope on a remote object, the Objective
Lens (08) may be in the wrong position, or may not be straight in the Body
(01).Disassemblethe telescope, and reassemblecorrectlyfollowing the
abovedirections.
GalileanHandTelescope
distance“d”
distance“D”

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#2 ATelescopic Magnifier
If you set the position of the Objective Lens (08) using the mark on the Rod
(16) as discussed in step 3 on page 7, the telescope is set for a focal length
that will focus on astronomical objects.However, if you position the Objective
Lens(08)farther from the DiversionLens Eyepiece (06), youwill set the
telescope for a focal length that is much shorter.
To make a Telescopic
Magnifier
1. InserttheObjectiveLens(08) into
the very end of the Body (01) at
theendwiththedecorative
covering.
2. InserttheDiversion Lens
Eyepiece (06) in the other end.
TheTelescopic Magnifier is best suited for looking at objects that are only 1/2
to 2 meters distant (approximately 1/2 to 6 feet).
The distances of the Objective Lens to the Eyepiece and the Objective Lens to
theobservedobjectare“inverselyproportional”.Thatmeansasonegets
larger, the other gets smaller in some mathematical relationship to each other.
When the Objective Lens was midway in the Body to make the Galilean
Telescope, we could call the small distance from the Objective Lens to the
Eyepiece distance “d”. We were able to focus on a distant object, like the
Moon. We can call that long distance to the Moon “D”.
With theTelescopic Magnifier, we increased the small distance“d”to the end
of the Body, so let’s call the new small distance “d+”.Now the distance to the
observed object is much smaller.Let’s call it distance “D-”.
So we learn that“d”and“D”are inverse to each other.As“d”became “d+”,“D”
became“D-”.Throughobservation,wecanlearnthatthey are also
proportional,thatmeansthedifferenceshaveamathematicalrelationship.
Thismathematicalrelationshipshown by telescopes of variouslengthsand
objectsof various distances opened the door forthinking about allsorts of
mathematicalrelationshipsinnature;andhelpedgenerationsofinspired
thinkerscreatethe foundations of modern science.
TelescopicMagnifier
distance“d+”
(08) (06)

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#3 Astronomical KeplerTelescope
JohannesKepler (1570-1630) wasaGermanscientist who livedduringand
afterGalileo’slifetime. Kepler was very interestedin Galileo’s work, and continued
toimprove the telescope. He iscredited with developing the Symmetric Lens, which
he described in his book“Dioptrics”which was published in 1611.
When you look at the cross section of the Symmetrical Lens Eyepiece
(07) in the diagram, notice that the space between the two opposite lenses is itself
shaped like a lens. Kepler is credited with recognizing that these “negative spaces”
can be as important in lens optics as lenses themselves.
In 1600 Kepler was invited to become assistant toTyco Brache,
mathematician at the court of Emperor Rudolph II of Prague.Brache’s most
important contribution to modern science was not theory, but his extensive
observations of the movements of the planets, which Kepler assisted him in
collecting.
The famous fictional 19th century sleuth Sherlock Holmes stated “ it is
uselessto theorize ahead of thefacts”. Brache refused toadvance theory of
planetarymotionuntilhehad made numerous observations himself, using Kepler’s
improvedtelescopes.EveryclearnightformanyyearsBrachecarefullyobserved
and plotted the relative locations of the known planets and prominent stars. By the
time of his death, he had compiled the most accurate and extensive record of
planetarymotionever made. But he hadnot proposed any additional theoriesto
explainthefactshehad observed.
At Brache’s death, his extensive records were inherited by Kepler.Kepler then
postulated his 3 laws of planetary motion. Later Isaac Newton built upon Kepler’s
lawsto form the basis ofmodern “Newtonian” physics.
To assemble a Kepler’s HandTelescope
1. Insert the Objective Lens (08) into
theendoftheBody(01) which has
thedecorativecoveringasyoudid
tomaketheTelescopicMagnifier.
2. Insert the Symmetric Lens
Eyepiece(07) in theother end of
the Body.
3. Adjust the position of the
Eyepiece (07) to focus the
instrument.
NOTE: The complex lenses in Kepler’s symmetrical eyepiece change the simple
“inverseproportion”calculations offocallength.However,if youdothemath,the
rules still apply.Also, the image seen in a Kepler’s telescope will be inverted.
Kepler’stelescope

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#4 A Terrestrial 10X Hand Telescope
Kepler’stelescope greatly improved on Galileo’sin terms of itsmagnification
andfield of view.However, Kepler’stelescope,likeGalileo’s produced an
inverted(upside down)image.
The inversion is caused by the convex sides of the magnifying lens directing
the light waves past each other, top to bottom and side to side.
Inversion Lenses (05) used in pairs can be used to make the image appear
through the telescope as it does in nature.
TheTerrestrial10XHandTelescope is usefulforseeingthingson earth,at a
distancegreaterthan10meters (32-1/2 feet).
ToassembletheTerrestrial10X Telescope
1. Fit the Objective Lens (08) into the Body (01) at the end with the decorative
covering.
2. Fit the short end of Collecting Lens (04) into the end of the Drawtube (02).
3. From the other end of the Drawtube, insert 13mm Spacer (12) until it touches
the end of the Collecting Lens.
4. Next insert Inversion Lens (05) with the marking toward Spacer (12).
5. Next insert 16.2mm Spacer (13)
6. Now insert the other Inversion Lens (05) with the marking “5”to the outside
facingaway from 13mm Spacer(12).
7. Insert the Symmetric Eyepiece (07).
8. Insert the Collecting Lens (04) into the Body (01) to join the two parts of the
telescopetogether.
You can now focus the telescope on objects more than 10 meters away by
adjusting the Eyepiece.
theTerrestrial 10XTelescope