National Optical & Scientific Instruments Inc.
6508 Tri-County Parkway
Schertz, Texas 78154
Phone (210) 590-9010 Fax (210) 590-1104
Copyright © 5/28/2010
National Optical & Scientific Instrument Inc.
Knurled diopter ring
Interpupillary scale
Widefield 10x/18
Viewing head of microscope
Head locking screw
Arm of microscope
Objective turret
Rack stop adjustment screw
Objective lenses
Specimen holder (mechanical stage)
Tension adjustment collar
(behind focus knob on left side)
Abbe Condenser
Coarse focus knob
Iris diaphragm lever
Swing-out filter holder
Fine focus knob
Illuminator field
lens housing
Light intensity control knob
On/Off switch
Recharging socket
For optimum viewing satisfaction, follow these simple procedures. Nomenclature used to describe components and
controls can be identified by referring to the diagram at left.
The microscope and accessories have been carefully packed to assure they reach you in the best possible condition.
Examine packing material before you discard it. Retain the styrofoam container in case you need to transport, store,
or return the microscope for service. If it becomes necessary to ship the microscope for any reason, pack it in the
styrofoam container, and then pack the styrofoam in another corrugated shipping container for optimum protection. Use of
the styrofoam alone will not provide adequate protection in transit, and will void your warranty.
Always handle and move microscope by securely holding the arm of microscope. Avoid touching any of the lens surfaces
while handling the microscope. Dust, dirt, or fingerprints can damage the delicate lens surfaces or adversely affect image
Model 215-RLED: Stand with head, two WF10x eyepieces, 4x, 10x, 40x and 100x objectives, condenser, recharger,
specimen holder, dustcover, 2mm “L” hex wrench (for rack stop adjustment), 0.90mm “L” hex key wrench (Lamp
1. EYEPIECES (ocular lens) Lens closest to the eye, magnifies the primary image formed by the objective lens. One
eyepiece is equipped with a “pointer” that rotates as the eyepiece is turned and one eyepiece without pointer.
2. OBJECTIVE TURRET (nosepiece) Revolving turret which holds objective lenses, permits changes of magnification by
rotating different powered objective lenses into optical path.
Lens closest to the object being viewed, forms first magnified image of the specimen.
Permits precise, mechanical manipulation of the specimen slide.
Platform of the microscope where the specimen slide is placed.
6. CONDENSER LENS 1.25 N.A. Abbe condenser lens positioned under center of stage, condenses light rays from
substage illumination and fills the back lens element of objective lens to improve image resolution.
7. IRIS DIAPHRAGM Iris opening is controlled by lever, designed to help achieve optimum resolution of the objective
lens. Larger apertures used for higher magnifications, and smaller apertures used for lower magnifications. Iris is
protected by a frosted glass covering.
8. FILTER HOLDER Attached to bottom of iris diaphragm with swing out built in neutral filter. Swing out filter should
be removed from optical path when using 40x and 100x objective lens.
9. SAFETY RACK STOP When properly adjusted, controls maximum upward travel of stage. Prevents higher power
objectives from breaking specimen slides, prevents damage to objective lenses. This stop has been pre-adjusted at
the factory.
10. FOCUSING KNOBS Coaxial focusing system combines both the coarse and fine focus knobs on same shaft located
on each side of arm. Raise or lower stage to bring specimen into focus.
11. ILLUMINATION Built-in substage electric LED illuminator provides constant, reliable, pre-focusing illumination equal
to a 20 watt tungsten bulb. Powered by 3 rechargeable AA nickel metal hydride batteries, no power outlet or electrical
cord are needed.
1. Eyepieces:
Remove the dust caps from eyepiece tubes and insert eyepieces.
Specimen holder:
Rotate coarse focusing knob to move stage platform to its lowest position. Remove two knurled screws from
mechanical stage platform. Place specimen holder on stage and using the two knurled locking screws, attach
specimen holder to mechanical stage
1. Place microscope directly in front of you in a manner which permits you to comfortably look into the eyepiece. Note
that the head of microscope rotates 360º, permitting you to operate the microscope from the front or from the back,
whichever is most convenient for you. It also permits convenient sharing of microscope by more than one user, by
simply rotating head, without needing to move entire microscope.
2. Assure that light is available for illuminating the specimen.
a. Your microscope has special LED illumination that is powered by 3 rechargeable AA nickel metal hydride batteries
(supplied). These batteries may be recharged, as required, using the recharger (supplied). Each set of batteries
may be recharged approximately 500 times before replacing, and each charge will provide up to 50 hours of
microscope operation. The LED component (bulb) will last for up to 50,000 hours before replacement is required.
DO NOT USE regular AA alkaline batteries. Use of other than rechargeable AA nickel metal hydride
batteries could result in batteries exploding during recharge. ONLY USE THE SUPPLIED SWITCHING
b. It is recommended that you charge the batteries before initial use and after prolonged storage as the batteries may
have discharged. Plug output cord from battery charger into DC recharging socket located on back of microscope
base. Your automatic switching recharger operates on 100 to 240 volts AC 50/60 Hz. Plug recharger into your AC
wall outlet. Battery recharger is also equipped with an automatic “trickle charge” feature, the red LED indicator
lamp located on recharger will be illuminated when batteries are receiving maximum charge. After batteries are
charged, the red LED indicator lamp will turn to green and charger automatically switches to “trickle charge”. The
charger can be left plugged in, but for safety reasons it is a good idea to disconnect the charger from the AC wall
outlet and the output cord from recharging socket after 12 hours. Batteries and charger may feel warm when
charging, and unplugging the recharger is a safety precaution.
Note that your microscope can be used during recharging. Simply turn “on/off” switch on back of microscope
base to “on” position and proceed as follows.
3. Interpupillary adjustment of head: Look through the eyepieces and move the eyepiece holder tubes by rotating them
on their axis. When a full field of view is observed through both tubes, and images blend into one, interpupillary
distance is corrected for your eyes. Check the interpupillary scale and note index reading for future reference, in case
other users will be changing this adjustment from time to time. Each person may have to adjust interpupillary distance
to receive the same image.
4. Rotate coarse focus knobs to move stage down (away) from objective lens as far as possible.
5. Position the objective turret until the 4x (smallest) objective lens “clicks” into position in the optical path. Note that
each time you change from one objective lens to another you should turn the turret until you hear the “click”, which
indicates that the lens is properly indexed in the optical path.
6. Swing moveable finger on slide holder outward. Place specimen slide (cover slip up) on top of stage surface against
fixed side of slide holder. Slowly release moveable finger until it makes contact with specimen slide.
7. Turn rheostat (dimmer) control in direction to reduce illumination brightness to about mid-point. Normally, brightness
will need to be reduced as magnification is reduced, and increased as magnification is increased. Experiment with this
adjustment until optimum resolution and contrast of specimen is obtained.
8. Locate lever beneath stage that controls the iris diaphragm. Move lever until iris diaphragm is about half open.
Normally, aperture of iris should become smaller for lower magnifications and larger for higher magnifications.
Experiment with this setting until optimum resolution and contrast of specimen is obtained.
9. While looking through the eyepiece, rotate coarse focusing knobs until specimen comes into focus. If image does not
appear in field of view, move specimen slide slightly until image appears in field of view.
10. Adjust fine focus controls until specimen is in sharp focus.
11. Changing magnification.
a. Magnification is changed by rotating objective turret until a different objective lens is moved into optical path.
Always turn turret until you hear the “click”, indicating that lens is properly indexed. Otherwise, you will not be able
to see anything when looking through the microscope.
Objective Specifications
Din 4X
Din 10X
Din 40X retractable
Din 100x retractable
Color Code
Field of
Magnification with
WF10X eyepiece
b. Also note that each objective has a color ring, which permits you to instruct changes in magnification by referring
to an easily observed color rather than to a number.
The microscope has been parfocalled at the factory, which allows easy change from one magnification to another,
requiring little or no adjustment of the fine focus knobs.
d. As magnification is increased, the field of view (area of specimen seen through the microscope) will decrease.
That is why it is easier to find the specific area of interest on the specimen by starting with the lowest 4x objective
lens, before increasing magnification with the higher power objective lens.
e. NOTE: Care must be taken when rotating the 40x and 100x objective lenses into place. These lenses have a
spring retractable mechanism, which retracts slightly into its housing if the front of the lens, strikes the specimen
slide. With fine focus adjustment at mid-range, the rack stop has been adjusted at the factory to assure the 40x
and 100x lens will clear the thickness of a normal specimen slide and cover slip. However, if the rack stop has
been improperly adjusted, or if using a thicker than normal slide or cover slip, moving the 40x and 100x lenses too
quickly or carelessly could cause damage to the front lens element or to the slide.
In order to obtain maximum resolution of the 100x oil immersion lens, it is necessary to apply immersion oil
between the cover glass of slide and front lens of the objective. Use a very small amount of immersion oil. All air
bubbles must be removed from between lens and slide by gently rotating nosepiece back and forth.
When you are finished viewing, all parts that come in contact with oil must be cleaned. Failure to do so could
permanently damage the 100x immersion objective lens.
Do not let the front lens element of the 40x objective lens come into contact with a wet slide surface, as prolonged
contact with any moisture could damage the lens. If lens is exposed to moisture, promptly wipe with soft tissue to
remove moisture.
WARNING: For your own safety, make certain that battery recharger is unplugged and removed from microscope
jack before maintaining your microscope.
Do not attempt to disassemble any lens components. Consult a microscope service technician when any repairs not
covered by instructions are needed.
Prior to cleaning any lens surface, brush dust or dirt off lens surfaces using a camel hair brush. Or use air to blow dust
and lint off surfaces. Use of compressed air in a can, available at any computer supply store, is a good source of
clean air.
Do not remove eyepieces or objective lenses to clean. Clean only the outer lens surface. Breath on lens to dampen
surface, then wipe with lens paper or tissue or use a cotton swab moistened with distilled water. Wipe lenses with a
circular motion, applying as little pressure as possible. Avoid wiping dry lens surface as lenses are scratched easily. If
excessive dirt or grease gets on lens surfaces, a small amount of Windex can be used on a cotton swab or lens
tissue. To clean objective lenses, do not remove objectives from microscope. Clean front lens element only, following
same procedure.
NOTE: Fingerprints or other matter on the front lens element of the objective lens is the single most common reason
that you will have difficulty in focusing the microscope. Before having costly servicing done, or before returning to
National for “warranty repair”, make certain to examine the front lens element with a magnifying glass or eye loupe for
the presence of such contaminants. If a microscope is returned to National for warranty repair, and it is determined
that such contaminants are the problem, this is not covered under warranty and National will submit a cost estimate for
a. The rack stop screw has been pre-adjusted at the factory and should not require re-adjustment. However, if you
do attempt re-adjustment, note the following procedure.
Using a 2mm “L” type hex key wrench, loosen rack stop hex socket set screw by rotating in a counterclockwise
direction. With fine focus adjustment at mid-range, focus on a standard slide until sharp image is obtained.
Rotate rack stop screw in clockwise direction until tight
b. Coarse focus tension adjustment prevents the stage from drifting down from its own weight and causing the image
to move out of focus. This has been adjusted at the factory, but over the course of time it may loosen and cause
the stage of the microscope to slip downward on the focusing block.
With stage facing you, the tension adjustment collar is located between arm and coarse focus knob on left side of
microscope. Turn collar counter-clockwise to tighten tension, clockwise to loosen tension.
NOTE: It is recommended that you leave the tension as loose as possible for ease of focusing, yet not so loose
that it permits the stage of microscope to drift downward from its own weight and cause the microscope to “drift”
out of focus.
Metal parts: Use a clean, damp cloth to remove dust or dirt from metal parts, followed by a dry cloth.
The extent of electrical maintenance, by other than a qualified technician, should be LED replacement, battery
recharging and battery replacement. Before maintenance, be sure that recharger is not connected to microscope.
a. Recharging batteries:
Plug output cord from battery charger into DC recharging socket located on back of microscope base. Your
automatic switching recharger operates on 100 to 240 volts AC 50/60 Hz, plug recharger into your AC wall outlet.
The red LED indicator lamp located on recharger will be illuminated when batteries are receiving maximum
charge. After batteries are charged, the red LED indicator lamp will turn to green and charger automatically
switches to “trickle charge”. The charger can be left plugged in, but for safety reasons it is a good idea to
disconnect the charger from the AC wall outlet and the output cord from recharging socket after 12 hours.
Batteries and charger may feel warm when charging, and unplugging the recharger is a safety precaution.
You may operate the microscope light even while it is being recharged. Simply flip light switch to “on” position and
continue using microscope while the recharger is fully engaged.
b. Replacing batteries:
Your microscope includes 3 rechargeable AA nickel metal hydride batteries. These may be recharged up to 500
times, but if you observe that a recharge is providing significantly less than 40 hours of operation. It is probably
time to replace to batteries.
Gently lay microscope on its side or back. Observe small door in center of microscope bottom base. Loosen
slotted screw on door and open. Battery case is mounted on inside of door. Using small Phillips screwdriver,
carefully remove Phillips screw that holds battery case together. Slide lid of case straight out to remove and
expose batteries. Remove all 3 batteries and replace with new rechargeable AA nickel metal hydride batteries,
making certain to insert with correct polarity according to markings on battery holder. Replace lid, close and
secure door.
Follow instructions on new battery packaging to determine if they are already charged, or if they should be charged
before initial use. If recharging is required, following directions in “3.a” above.
Replacing LED element:
An LED “bulb” will last up to 50,000 hours, so you don’t have to do this exercise very often.
To open the illuminator field lens housing, use hex wrench supplied with your microscope to loosen the two hex
screws on side of lens housing. Remove lens housing to expose LED “bulb.” Remove bulb by grasping the
plastic base of bulb and gently pulling straight up. Insert new LED “bulb”, replace lens housing and tighten hex
screws to secure lens housing in place.
Light fails to operate.
Image does not remain in focus
Image will not focus
Poor resolution
(image not sharp)
Spots in field of view.
Batteries fully discharged.
Recharge batteries.
Rheostat control not turned far
Turn rheostat to increase light
Light switch in ‘off’ position.
Turn light switch on.
LED “bulb” burned out.
Stage of microscope drops from
its own weight.
Rack stop not set at proper
Replace LED “bulb”.
Adjust tension control.
Slide upside down.
Place slide on stage with cover
slip up.
Slide cover slip too thick.
Objective lenses dirty.
Use 0.17mm thick cover slip
(No.1 cover slip)
Clean objective lenses.
Eyepiece lens dirty.
Clean eyepiece lenses.
Too much light.
Eyepiece or condenser lens dirty.
Adjust diaphragm.
Clean lens. ***
Adjust rack stop.
Specimen slide dirty.
Clean slide.
***Spots in field of view can also result from dirt on inside of eyepiece. It is recommended that you have
service technician clean inside of lens.
WF10x eyepiece w/reticle, 10mm/100div.
WF15x eyepiece w/pointer
DIN 60xR objective lens, N.A. 0.90
Replacement LED light
Replacement auto-cut off recharger for rechargeable LED microscope
Dustcover, 16” tall x 13”, heavy vinyl with stitched seams.
Carrying case, anodized aluminum, fabric lining, accessory pockets, Velcro straps, keyed lock.
Please see our website,, for complete warranty details and exclusions.
(Revised 4/16/13)