Having worked in the video measuring machine industry for over twenty years, I’ve seen many devices measure accurately—or fail to do so. Ultimately, the key is the position feedback system, and the optical scale is one of its most critical components. Our machines use imported open-type precision optical scales with a 0.5 μm resolution. This specification is not just for show—it really matters.
The Practical Value of Resolution
0.5 μm, or 0.0005 mm, is highly significant in precision measurement. For example, in plastic molds, a wall thickness variation of 0.02 mm can cause assembly issues; in bearing balls, a diameter tolerance of ±5 μm affects noise and lifespan. With a 0.5 μm resolution, the machine can detect these tiny variations instead of producing rough approximations. Of course, high resolution does not automatically mean high accuracy, but it is the foundation—like a microscope lens: it must be clear before you can focus.
Advantages and Challenges of Open-Type Optical Scales
Open-type optical scales lack a fully enclosed housing, making them compact, flexible, and fast in response—ideal for small gantry or compact machines. In my experience installing them, the benefit is easy adjustment without dismantling half the machine. The downside is that they are sensitive to dust and oil mist; contamination can cause reading drift. I once had a customer whose workshop had heavy oil mist, and within three months, the scale was dirty, and precision dropped. Adding a transparent protective cover stabilized performance.
Usage and Maintenance Tips
Environment: Use protective covers in dusty or oily areas to minimize contamination.
Cleaning: Clean every 3–6 months with a lint-free cloth and dedicated cleaning solution; avoid abrasive materials.
Shock Protection: Lock the axes during transport and setup to prevent damage to the read head.
Temperature: Ideal in a temperature-controlled room; if the workshop has large temperature variations, add compensation or insulation.
A 0.5 μm imported open-type optical scale allows a video measuring machine to balance precision and speed. However, it demands proper environment and maintenance. Proper installation and usage are key—reliable performance comes from real-world stability, not just specifications.