Imported industrial microscope is a precision instrument used for observing and analyzing small objects or structures. Its working principle is based on optical or electron optical principles, which magnifies and presents clear images of the microscopic world that is invisible or difficult to observe directly.

（1） Optical imported industrial microscope

1. Lighting system: Kohler lighting method is usually used. The light emitted by the light source uniformly illuminates the observed object through a spotlight. The function of a spotlight is to adjust the angle and intensity of light, so that the light shines on the object at an appropriate angle, ensuring that all parts of the object receive uniform and sufficient illumination.

2. Objective imaging: The objective lens is one of the key components of an optical microscope. It is close to the observed object, with a shorter focal length and higher magnification. The objective lens magnifies the object for the first time, forming an inverted real image. This real image is located inside the focal point of the eyepiece. The quality and performance of the objective lens have a crucial impact on the clarity, resolution, and other aspects of imaging. For example, high-resolution objective lenses can distinguish smaller object details.

3. Eyepiece observation: The function of the eyepiece is to further enlarge the image formed by the objective lens. There is one or more lens combinations inside the eyepiece, which magnifies the real image formed by the objective lens again and corrects any aberrations that may occur during the imaging process of the objective lens.

（2） Electronic imported industrial microscope

1. Transmission Electron Microscope (TEM)

-Electron beam emission: High speed electron beams are emitted by an electron gun. Electron guns generally have two types: hot cathode emission type and field emission type. The hot cathode emission type uses heating materials such as tungsten wires to emit electrons, while the field emission type uses a strong electric field to extract electrons from a sharp emitter surface. These electrons have high energy.

-Sample interaction: A high-speed electron beam passes through an ultra-thin sample (usually with a thickness in the nanometer range). During the process of passing through the sample, electrons collide with atoms in the sample. Due to the different atomic densities and atomic numbers in different parts of the sample, the degree of electron scattering also varies. This scattering can cause changes in the intensity and phase of the electron beam, carrying information about the internal structure of the sample.

-Imaging system: The electron beam passing through the sample is focused and imaged by an electromagnetic lens system. Electromagnetic lenses use the magnetic field generated by current passing through coils to refract electron beams, similar to the principle of optical lenses refracting light, but with more flexible control. By adjusting the current of the electromagnetic lens, the focal length and focusing effect of the lens can be changed, forming an image reflecting the internal structure of the sample on a fluorescent screen or photographic film.

2. Scanning Electron Microscope (SEM)

-Electron beam scanning: The electron beam emitted by the electron gun scans the surface of the sample point by point under the action of the scanning coil. The electron beam spot is very small and can usually be focused to a size of several nanometers.

-Signal collection: When the electron beam is irradiated onto the surface of the sample, it will excite the sample to produce various signals, such as secondary electrons, backscattered electrons, etc. Secondary electrons are low-energy electrons emitted from atoms on the surface of a sample after being excited by an electron beam, which can well reflect the morphological characteristics of the sample surface. Backscattered electrons are electrons that return after elastic scattering between incident electrons and sample atoms. Their yield is related to the atomic number of the sample and can be used to analyze the composition distribution of the sample. These signals are collected by corresponding detectors.

-Imaging display: The signals collected by the detector are amplified and processed to form images on the display in the order of electron beam scanning. By adjusting the parameters of the electron beam and the receiving method of the detector, images with different contrasts and information can be obtained for studying the surface morphology, composition, etc. of the sample.