1. About instrument placement
Whether it is a computer focimeter or a manual focimeter, as a precision optical device, it should be handled with care when using and operating, and try to avoid excessive movement. The position where the focimeter is placed should avoid direct sunlight, so as not to interfere with the wavelength of the light wave (green mercury line λe=546.07nm) displayed by the focimeter, causing it to not work properly.
2. About instrument operation
When the surface of the optical components of the focimeter reading system is stained with dust, oil, and fingerprints, the optical system will not be imaged clearly; when the lens is not placed, the center of the reticle of the marking reticle and the center of the eyepiece reticle do not coincide; due to the rotation The idle rotation and eccentricity of the wheel cause gaps between mechanical parts and cause zero error and indication error, etc. These problems are inseparable from the user's usual bad operation and rough operation.
Therefore, the personnel using the focimeter should develop good operating habits, try to avoid excessive operation and blind operation that may cause damage to the mechanical parts, and pay attention to daily cleaning and maintenance. In this way, whether it is a manual focimeter of several thousand yuan or a computerized focimeter of tens of thousands of yuan, it can achieve "longevity and longevity".
3. Setting of the internal parameters of the instrument
In recent years, with the intensified competition among the eyewear retail industry, people's brand awareness has been strengthened day by day, in order to establish a good corporate image and win more customers and business opportunities. Many optical shops have purchased autofocus focimeters that are more accurate and easier to use. However, the convenience and accuracy brought by the high price should be based on the correct setting of the internal parameters of the computer.
Among them, the selection of the indication interval (generally can be debugged to 0.01D) is particularly important. In actual work, the indication interval of the computer focimeter in some optical retail stores is still placed on the 0.12D or higher 0.25D. In this way, not only the role of high-precision instruments is completely buried, but also the control of the lens vertex power tolerance specified in GB10810-1996 "spectacle lenses" (GB10810-1996 "spectacle lenses" The provisions in the national standard: within the nominal value of the spherical vertex power of the spectacle lens (0.00 to 9.00) D, the spherical lens tolerance is determined to be ±0.12D). If the single-item system error caused by improper setting has exceeded the tolerance specified by the national standard, what is the responsibility and integrity to the customer! Therefore, it is necessary to emphasize again that as long as the computer focimeter can be debugged to a 0.01D interval, it must be Adjust its indication to this gear.
In addition, the Abbe number is an important parameter in lens design, and it is also a factor that cannot be ignored in the inspection. Due to the improper setting of the Abbe number, the systematic error caused by man will exceed the accuracy of the instrument's indication value (0.01D), which naturally affects the scientificity and accuracy of the measured data.