The polarizer axis position tester uses the principle of optical polarization to detect the axis position of the lens. The cleanliness of its optical components and key areas directly affects the measurement accuracy. It can be judged whether cleaning is needed by observing the appearance, detecting data, and checking the operating status of the equipment. The specific steps are as follows:
Observe the appearance stains of the core components
The optical components of this type of tester are the key observation points for determining whether to clean. On the one hand, looking at the stage, if there is dust, fingerprints, residual wiping paper scraps or oil stains on the platform where the lenses are placed, it will cause the lenses to not fit the platform when placed, indirectly affecting the alignment of the optical axis; On the other hand, when examining core optical components such as polarizing lenses and detection lenses, if foggy stains, impurities attached to scratches, or obvious dust particles can be seen on the surface of the lens through the observation window, these impurities will block and refract polarized light, interfering with the normal propagation of light. At this time, it is necessary to clean them in a timely manner.
Judging based on abnormal measurement data
If the measurement data is unstable or deviates beyond the standard, after excluding problems with the lens itself and equipment calibration, it is highly likely that the instrument needs to be cleaned. For example, when testing with a standard polarizer with known standard axis positions (such as 0 °, 90 °, 180 °), the axis deviation displayed by the instrument continues to exceed ± 0.5 °, and the deviation does not improve after multiple measurements; Or when measuring the same lens, multiple readings may fluctuate greatly, making it difficult to obtain stable and similar results. In addition, if it is difficult to find a clear extinction position during measurement and the boundary between light and dark is blurred when viewing objects, it can lead to difficulties in determining the axis position. This is also a signal that the optical components of the instrument have stains and need to be cleaned.
Auxiliary judgment based on device operating status
Some polarimeter axis testers with automatic positioning and light adjustment functions can also reflect cleaning needs if their operating status is abnormal. For example, after the instrument is started, the light adjustment module frequently self checks but cannot reach the set light intensity; Or it may freeze during autofocus, making it difficult to quickly focus on a clear measurement field of view. This may be due to dust and other impurities blocking the light sensor, or adhering to the gaps of the adjusting components, affecting the normal operation of the components. In this case, it is necessary to clean and inspect the relevant components.