Measurement and Uncertainty Analysis of Indication Error of Microscope Objective Magnification
overview
Since the birth of the first microscope, microscopes have been widely used in teaching, medical treatment, scientific research and other fields. With the continuous development of science and technology, the use of microscopes has become more and more extensive. For example: in the production process of some products, it is often required to inspect the parts under a specific visual magnification. Therefore, in order to ensure the quality of the produced products, the accuracy of the observation instrument must be ensured first. For example, for a microscope, how can we know whether its magnification has reached the specified tolerance? This paper introduces a method for measuring the error of the indication value of the magnification of the microscope objective lens, and analyzes its uncertainty.
Measuring tools and measuring methods
The calibration device composed of a standard glass linear ruler (accuracy: 0101mm, measuring range: 0mm～1mm) and a micrometer eyepiece (magnification: 10 ×, measuring range: 0mm～16mm) can complete the display value error of the magnification of the microscope objective lens determination. Replace the eyepiece that comes with the microscope with a micrometer eyepiece with a scale, and combine it with the original objective lens to obtain different magnifications required. Using the direct measurement method, observing the difference between the magnification of the glass linear ruler and the nominal magnification of the microscope objective lens can determine whether the magnification of the microscope meets the specified requirements.
Uncertainty Analysis
1 Mathematical model:
Δτ=τs - τ
In the formula: Δτ—indication error of objective magnification, mm;
τs — the nominal value of the magnification of the objective lens, mm;
τ—measured value of objective lens magnification, mm.
Note: The relationship between the magnification of the objective lens and the length is obtained by converting the magnification of the micrometer eyepiece and the scale.
100mm.
2 The source of the uncertainty of the input τ is mainly the magnification of the microscope objective lens
The non-repeatability of the measurement of the multiple indication error and the uncertainty of the fixed value of the micrometer eyepiece and the standard glass linear ruler can be evaluated by the methods of type A and type B respectively and can be synthesized.
