The secondary imaging instrument is a precision measuring instrument, which measures and analyzes the image of an object to get the shape, geometric dimensions and other parameters of the object. This kind of instrument is widely used in machinery manufacturing, electronics, automotive, aerospace and other fields, and plays an important role in the quality control of products and the optimization of the production process.

The role of the lens is crucial in a secondary imager. It not only needs to focus the image of the object on the image sensor, but also needs to ensure the clarity and accuracy of the image. The quality of the lens directly affects the measurement accuracy and stability of the secondary imaging instrument.

There is a wide variety of lenses available on the market, including fixed-focus lenses, telecentric lenses, and zoom lenses. However, zoom lenses are often considered the preferred choice in secondary imagers. This is because zoom lenses offer the following advantages:

1. Flexibility: the zoom lens can be changed within a certain range of magnification, so that the secondary imaging instrument can be adapted to the measurement of different sizes and distances of the object. This improves the scope of use and flexibility of the instrument.

2. High precision: the optical design and manufacturing process of the zoom lens is usually more complex, which makes it have a higher imaging quality and precision. In the quadratic imaging instrument, the high precision lens can ensure the accuracy and stability of the measurement results.

3. Good stability: Because the optical structure of the zoom lens is more stable, so its performance is less affected by the ambient temperature and humidity. This allows the secondary imaging instrument to provide stable measurement results in a variety of environments.

In a secondary imaging instrument, choosing the right lens is the key to ensuring measurement accuracy and stability. Through the use of a zoom lens, the secondary imaging instrument can adapt to the measurement of objects of different sizes and distances, improving the scope of use and flexibility, while ensuring the accuracy and stability of the measurement results. This is an important role for product quality control and production process optimization in the fields of machinery manufacturing, electronics, automotive, aerospace and so on.