Applicable equipment: biological microscope, metallographic microscope, stereomicroscope Applicable scenarios: teaching training, equipment operation assessment, laboratory specification management
I. Optical Microscope Core Technical Terms (Interpretation Comparison Table)
Total magnification = eyepiece magnification × objective magnification, which only represents the image magnification size. If the magnification is too high, invalid magnification will occur, and the clarity will not be improved.
The core parameters of the objective lens directly determine the resolution size; the larger the NA value, the stronger the resolution of the microscope, and the finer the imaging
The microscope can distinguish the minimum distance between two adjacent tiny particles, which is the core indicator for determining the imaging accuracy. The calculation formula is: d = 0.61 λ/NA
The sample can maintain a clear imaging thickness range in the axial range; the stereomicroscope has a large depth of field and is suitable for concave and convex samples; the metallographic microscope has a small depth of field and can only observe flat samples.
Eyepiece core parameters, determine the observation field of view; actual field of view diameter = number of fields of view ÷ objective magnification
The vertical distance between the end face of the objective lens and the surface of the sample, the working distance of the high-power objective lens is extremely short, and the operation is easy to collide and damage the lens.
Eyepiece for human eye observation, conventional 10 ×; objective lens determines imaging quality and accuracy, divided into low magnification, medium magnification, high magnification, oil lens
Coarse focus: large range of fast focus, low magnification only; fine focus: tiny precision focus, high magnification only focus mode
Concentrate the light of the light source, improve the brightness and uniformity of the imaging, and adapt to different objectives by adjusting the height
Aperture diaphragm: controls beam size, affecting resolution and contrast; Field of view diaphragm: controls illumination spot range, reducing stray light
Light Penetrating Sample Imaging for Biological Microscopy, Observing Transparent, Translucent Flake Samples
The light source irradiates the sample vertically through the objective, reflective imaging, suitable for metallurgical microscopy, observation of opaque samples such as metals
Bright field: general basic imaging mode; dark field: black background image, observation of tiny impurities, scratches; polarization: observation of crystals, stress, anisotropic materials
Correcting the image ratio with a standard ruler to ensure the accuracy of the software measurement is a necessary step in microscopic measurement
Simply increase the magnification, do not increase the resolution, only enlarge the image size, the picture is blurred, no details, no observation significance
II. Standard Operating Procedures for Microscopes (General Specifications)
Core operating principles: first low times, then high times; first coarse adjustment, then fine adjustment; high times forbidden coarse adjustment
Power on the device, turn on the light source and adjust it to medium brightness; install the 10 × eyepiece, switch the 5 ×/10 × low-power objective lens and clamp it tightly; fix the sample observation surface upward on the stage
Do not turn on the direct maximum brightness to avoid damage to the light source; the objective must be locked in place to avoid imaging offset
Observe the objective on the side, rotate the coarse adjustment to bring the lens closer to the sample; observe the eyepiece, rotate the coarse adjustment in the reverse direction to find the outline of the sample, and use fine adjustment to focus clearly; adjust the condenser and diaphragm to optimize the image quality, and calibrate the binocular parallax
The collision avoidance glass must be observed on the side; all samples must be positioned at a low magnification first, and direct high magnification observation is prohibited.
Move the observation target to the center of the field of view under the low magnification mirror, rotate the converter to switch the 20 ×/50 × high magnification objective; use only the fine-tuning knob to fine-tune until the image is clear, match the adjustment aperture stop
High-power objective lenses are strictly prohibited to use coarse adjustment knobs, which are extremely easy to crush the sample and damage the lens.
4. Exclusive operation of oil lens (100 ×)
Turn on the objective after positioning the high magnification mirror, and drip the special mirror oil into the sample observation point; switch the 100 × oil lens, soak the lens in oil droplets, and fine-tune the focus; after the observation is completed, wipe the lens and the sample with lens paper + anhydrous ethanol.
Do not dry wipe the lens; residual lens oil should be cleaned thoroughly to avoid lens corrosion
Set the brightness of the light source to the minimum and turn off the power of the device; reset the objective to the low gear and remove the sample; clean the stage and lens and cover the dust cover
Do not directly cut off the power; the equipment does not need to be cut off for a long time to prevent dust, and daily maintenance is done.
• Adapts to opaque solid samples such as metals, alloys, etc. using reflective illumination without the need for a transmissive light source
• The sample needs to be polished, corroded, and the surface is smooth, otherwise the grain and texture cannot be observed
• The depth of field of the device is very small, and the surface of the sample can be slightly undulated, which can cause local blurring. Ensure that the sample is flat when observing.
• Kohler lighting should be debugged before observation to ensure uniform light in the field of view and improve the contrast of tissue imaging
Use only special lens paper, gently wipe with grease and absolute ethanol
Strictly follow the operation sequence of low magnification positioning and high magnification
Match objective magnification adjustment, balance resolution and picture face contrast
After observation, directly shut down the machine, the objective lens stays in a high magnification position
Dim the light source, reset the low magnification objective, shut down after cleaning the equipment
ST128Z Electronic Universal Stent Stereo Microscope
V. Equipment Core Distinction Shorthand (Stereoscopic/Metallographic/Biological)
1. Stereo microscope: large depth of field, strong stereoscopic feeling, low resolution, used for appearance, fracture, macro inspection of solder joints, no fine tissue observation ability 2. Biological microscope: Transmitted light imaging, used for transparent biological sample observation, medium magnification, imaging flatness 3. Metallographic microscope: Reflected light imaging, high resolution, small depth of field, for metal grain, coating, microstructure detection
Tell us the material, the feature you need to see and the magnification range. We will recommend a configuration and quote it.
