How to prevent dust in optical microscopes
It is extremely difficult to remove dust from the surface of optical components, so it is crucial to prevent dust from falling into the lens barrel, objective lens body, and all optical path pipelines. Therefore, microscope operators must develop a lifestyle habit: always pay attention to dust prevention. For example, when unscrewing the objective lens, it must be placed upside down on a clean tabletop or immediately inserted into the objective lens box; Please refer to the method of removing the eyepiece, and cover the opening of the eyepiece with a simple stopper or a clean paper cap at will; When replacing the microscope photography dark box, photomultiplier, and light bar base, cover the connection cover with your hands and never leave any gaps that fall into the dust; When pulling out the filter and the insertion plate, immediately block the insertion plate hole. Once dust is found on the optical surface of the lens, prism, and reflector, use an ear wash ball to repeatedly blow until the dust particles are completely eliminated. When some dust particles still do not fall off, they can be cleaned with a clean, dry, and soft brush. Of course, this kind of cleaning work is extremely troublesome and requires special patience. Never rub hard with fingers or rough cloth.
When the surface of the optical device is contaminated with oil, it is necessary to clean the oil and pay special attention to protecting the optical smoothness of the mirror surface. The front lens of the oil immersed objective lens needs to be cleaned frequently. After each use of this type of objective, it should be wiped clean and never let the oil dry on the surface of the objective. The commonly used method for this is to drop a drop of pure xylene on the lens wiping paper, place it on the front lens of the objective lens, and gently use your fingers to press and pull the lens wiping paper once or several times. The front lens of the objective lens must not be wiped with a coarse cloth or rubbed with fingertips. The degree of damage to the optical surface caused by coarse fibers and keratinized epidermal cells of fingers is very serious. A scratch on the optical surface is enough to dry the concentric stroke of the imaging beam.
In daily work, it is often easy to stain the dry objective lens with lens oil, so when the microscope field of view is not clear, the objective lens should be removed for inspection. The inspection method is not complicated. First, take off the objective lens and hold it with your hand while holding the eyepiece. The front lens of the objective lens should be facing upwards, and the contact lens of the eyepiece should be facing downwards. Align the objective lens and observe whether it is contaminated under oblique light. The inspection result indicates that the oil has been removed, but if there are still color marks left after xylene volatilization, gently wipe it with soft deer skin. The fibers of kneaded leather are much softer than those of fine silk fabric. In daily work, it is common to encounter untrained microscope operators wiping the objective lens with their fingers or rough wiping with a coarse cloth, which is an absolutely unacceptable bad habit.
When the mirror surface of the reflector, spotlight, and prism is not clean, the following formula can also be used to prepare cleaning solution for cleaning:
Sodium methylacetate 65%
Ethanol 30%
Diethylether 5%
When wiping the surface of optical components, special attention should be paid to maintaining the original position and angle of each optical component. During the cleaning process, if a component is touched and deviates from the optical path, please do not repair it yourself.
