Three methods of calibration of microscopes
Biological microscopes are widely used in histology, cytology, parasitology, microbiology, oncology, immunology, genetic engineering, botany and other fields. In order to obtain clear and bright ideal images and satisfactory microscopy results, resolution is the most important indicator of observation results. From a physical point of view, the resolution of biological microscopes is limited by the interference phenomenon of light and the performance of the objective lens used. Therefore, various optical technical parameters of the biological microscope should be calibrated according to the standards, and quality control should be taken for the items that involve accurate quantitative requirements in the calibration process to ensure the accuracy and reliability of the measurement results.
Calibration methods for biological microscopes
1. Appearance
Biological microscopes should be marked with information such as name, model, serial number, and manufacturer. The imaging of the optical system in the entire field of view should be clear, and there should be no shadows or reflected light spots that affect the observation in the field of view. The clear area of imaging should be concentric with the field of view.
The movement of each part of the biological microscope should be flexible and stable, without sticking and beating, and the illumination in the field of view should be uniform. The spectral colors of the left and right systems of the binocular microscope should be basically the same, with no obvious difference between light and dark.
2. Fine-tuning the interval between the handwheel and the engraved line
The fine-tuning handwheel should be flexible and stable, with moderate tightness. For fine-tuning the interval between the marking lines of the handwheel, measure the starting, middle and end positions of the handwheel. Before measurement, fix the indicator on the biological microscope with a special fixture to ensure that the indicator and the microscope are fastened and firm. When fixing the indicator, ensure that the measuring head is in vertical contact with the stage. Adjust the focusing handwheel of the biological microscope to zero the reading of the indicator. Rotate the focusing handwheel 10 scales, read the indicated value, and take 1/10 of the indicated value as the measurement result. The average value of the measurements at the start, middle and end positions is used as the calibration result.
3. The magnification error of biological microscope objective lens
Adjust the light source to an appropriate position, install the eyepiece with a scale reticle on one of the sleeves of the biological microscope, place the standard glass scale on the stage, and adjust the eyepiece and the standard glass ruler so that the reticle line matches the standard. The scale lines of the glass ruler are parallel to avoid measurement errors. Adjust the stage so that the zero position of the glass ruler is aligned with one end of the reticle, and then read directly.
