Common Troubleshooting and Precautions of Microscope

Common Troubleshooting and Precautions of Microscope  

1. The slide of the lens cylinder  

This is one of the frequent failures of biological microscopes.  The solution to the axle-sleeve structure of the microscope can be divided into two steps.  

Step 1: Hold the two rough-adjusted handwheels with both hands and tighten them with relative force.  See if it can solve the problem, if it can not solve the problem, it is necessary to use a special double column plate hand to screw down a coarse adjustment handwheel, add a friction plate, after the handwheel is tightened, if it is difficult to rotate, the friction plate added is too thick, you can replace a thin one.  With the handwheel rotation is easy, the mirror cylinder moves up and down easily, and does not slide by itself.  Friction plates can be punched with a hole puncher using waste photographic plates and soft plastic sheets less than 1 mm thick.  

The second step: check the gear on the rough adjustment hand wheel shaft and the rack on the mirror cylinder body meshing state.  The moving up and down of the mirror cylinder is accomplished by a rack driven by a gear.  Theoretically speaking, the best meshing state of gear and rack is that the indexing line of rack is tangent to the indexing circle of gear.  In this condition the gears turn easily and wear the most on the rack.  It is a mistake to put a gasket behind the rack so that the rack presses against the gear tightly to stop the barrel slipping.  The indexing line of the rack then intersects the indexing circle of the gear, and the tooth tips of the gear and rack are firmly against each other's tooth roots.  When the gears turn, they grind heavily against each other.  Since the rack is made of copper, the gear is made of steel.  So the grinding between each other, will wear down the teeth on the rack, the gear and rack will produce a lot of copper chips.  Eventually the rack will be so worn out that it can't be used.  Therefore, do not use a high rack to prevent the slide of the mirror barrel.  To solve the sliding problem of the mirror cylinder, we can only increase the friction between the rough-adjusting handwheel and the eccentric shaft sleeve.  There is one exception, however, where the indexing line of the rack is separated from the indexing circle of the gear.  At this time, when rotating the coarse adjusting handwheel, the phenomenon of idling and skidding will also be produced, which will affect the upward and downward movement of the mirror barrel.  If this is done by adjusting the eccentric sleeve of the roughing handwheel, the meshing distance between the gear and rack cannot be adjusted.  The rack can only be padded with appropriate slices to solve the problem.  Add gasket to adjust the gear and rack meshing distance of the standard is: it is easy to rotate the rough adjustment handwheel, but not idling.  

After adjusting the distance, add some neutral grease between the gear and rack.  Just move the cylinder up and down a few times.  Finally, the two compression screws on the eccentric bushing must be tightened.  Otherwise, the eccentric bushing may follow the rotation of the coarse adjusting handwheel, and the rack will be stuck, so that the mirror can not move up and down.  At this time, if the rough adjustment hand wheel rotation force is too large, it may damage the rack and eccentric sleeve.  After tightening the screw, if the eccentric sleeve is found to still follow it.  This is because the screw hole thread of the pressing screw is not corrected.  Because the manufacturers change the thread is to use the machine to change the thread, there are often one to two teeth did not change the thread in place.  At this time, even if the screw is not in place, the eccentric bushing is not tight.  Discover this kind of fault, as long as use the M3 thread tap to tap the screw hole thread can solve the problem.  With this method, I completely solved the problem of the eccentric bushing of 30 sets of biological microscopes in our school.  

After these steps are done one by one, the sliding problem of the mirror cylinder will be solved.  

2. Light shield positioning failure  

This may be the sunshade fixing screw is too loose, positioning marbles out of the positioning hole caused.  Just put the marble back into the locating hole and tighten the setting screw.  If it is difficult for the shader to rotate after tightening, add a washer between the shader and the carrier.  After the thickness of the gasket is tightened by screws, the light shield rotates easily and the positioning marbles do not escape. It is better that the light shield is positioned correctly.  

3. The objective lens converter is difficult to rotate or fails to locate  

Difficulty in turning the converter may be due to tight setting screws.  Makes it difficult to turn and can damage parts.  If it is too loose, the bearing balls in it will break off track and be crowded together, also making it difficult to rotate.  In addition, marbles are likely to get outside. Marbles are only one millimeter in diameter, so they are easy to lose.  The degree of tightness of the fixed screw is based on the ease of rotation of the converter, and there is no loose clearance in the vertical direction.  After adjusting the fixing screw, the locking screw should be tightened immediately.  Otherwise, when the converter rotates, problems will occur again.  

Transducer positioning failure may sometimes be caused by positioning reed fracture or elastic deformation.  Generally as long as the replacement of the reed on the line.  

4. The lens of the eyepiece objective is contaminated or moldy  

Most microscopes will get stained or mouldy on the outside of the lens after being used for a while.  In particular, the high power objective 40X was easily contaminated by sugar solution when doing the experiment of "observing the separation and restoration of the plasmid wall of plant cells".  If the lens is contaminated and not cleaned in time, mildew will occur.  The way of processing is to dip in with clean soft silk cloth first warm water cleans the pollutant such as sugar liquid, dry silk cloth is wiped with dry hind, reuse long fiber absorbent cotton dips in some of lens clean fluid is cleaned, blow dry with blow air ball finally.  It should be noted that the cleaning fluid must not seep into the objective lens inside.  In order to achieve the required magnification, the lenses of the high power objective lens need to be glued together tightly.  The glue is transparent and very thin. Once the glue is dissolved in solvents such as alcohol and ether, the light path will change as it passes through the two lenses.  Observations are greatly affected.  So do not let alcohol, ether and other solvents into the inside of the objective lens when cleaning.  

If the eyepiece, objective lens lens inside the lens is contaminated or mildew, it must be disassembled and cleaned.  The eyepiece can be directly unscrewed and removed for cleaning.  But the structure of the objective lens is more complex, the stack of the lens, the distance between the lenses have very strict requirements, and the accuracy is very high.  The manufacturer is precisely calibrated at the time of assembly.  Therefore, after disassembling and cleaning, it must be assembled strictly as is.  

The lenses of biological microscopes are all made of finely processed optical glass sheets. In order to increase the light transmittance, a very thin film is applied on both sides of the optical glass sheets.  In this way, the transmittance can reach 97 to 98 percent.  This layer of transmittance film surface is very smooth, and very thin, once the surface of the transmittance film is scraped to leave traces, its transmittance will be greatly affected.  It becomes blurred when you look at it.  When wiping lens so, must use clean soft silk cloth or clean brush to wipe gently, if use to wipe lens paper to wipe more to wipe gently, lest damage pervious to light film.  

5. The lens frame can not be fixed when the hip tilts  

This is caused by the loosening of the connecting screws between the frame and the base.  You can tighten the two holes of the binocular nut by using a special double-headed plate hand or a tip clamp.  If the problem is not solved after tightening, appropriate gaskets should be added to the nuts to solve the problem.  

When the image on the screen is cut, consider whether the pull rod is moving in place;  If not, move the corresponding tie rod into position.  

6. Dirty spots were found during use  

If found a dirty spot on the display image, then consider whether specimen has stolen goods, if found inside the specimen not stolen goods, to check the lens surface to have stolen goods, if you have stolen goods will show a dirty point on the display, the solution is simple, as long as the surface of the lens and the stolen goods cleared in the specimen.  

7. The image is not clear when adjusting zoom  

If you find that the image is not clear when adjusting the zoom, check whether the high zoom is clear or not. If not, just set it to the highest zoom, and then refocus it.  

Matters needing attention  

When holding the mirror, it must hold the arm with the right hand and the rest with the left hand, and can not be extracted with one hand, so as to avoid the parts falling off or colliding with other places.  

Handle with care, do not put the microscope on the edge of the experimental platform, should be placed 10cm away from the edge, so as not to knock down the ground.  

Keep the microscope clean, optical and lighting parts can only be wiped with a mirror wipe paper, do not blow mouth hand wipe or wipe with a cloth, mechanical parts with a cloth to wipe.  

Do not touch the lens and lens with water, alcohol or other drugs. If it is stained, it should be cleaned immediately with polishing paper.  

When placing the slide specimen, aim at the center of the light hole, and do not put the slide backwards to prevent the slide from being crushed or the objective lens from being damaged.  

To develop the habit of observation with both eyes open at the same time, with the left eye to observe the field of vision, the right eye for drawing.  

Do not take off the eyepiece at will to prevent dust from falling into the objective lens, and do not arbitrarily disassemble various parts to prevent damage.  

After use, it must be restored to put back into the box, the steps are: take the subscript film, turn the rotator to make the lens leave the light hole, lower the mirror, lay the mirror flat, lower the light collector (but do not contact the mirror), close the aperture, push the film device back, cover with silk and cover, put it back into the laboratory cabinet.  Finally fill in the registration form.  (Note: the reflector should normally be placed vertically, but sometimes because the concentrator is not lifted to the due height, the aperture will be damaged when the lens drops, so here it is changed to flat)