Metering rods can be classified based on surface structure and application scenarios. By surface structure, they are primarily categorized into wound rods, extruded rods, and smooth rods. Wound rods are relatively inexpensive, offer moderate precision, and are suitable for general coating applications; extruded rods carry no risk of wire breakage, provide high precision, are easy to clean, and are suitable for precision coating and ultra-thin coating; smooth rods are used for hydrodynamic metering and are suitable for scenarios requiring extremely thin coatings or smooth surfaces
Based on application scenarios, they can be categorized into laboratory-use and industrial-production-use types. Laboratory-use metering rods are typically shorter, ranging from 100 mm to 400 mm in length, and are used for preparing standard test specimens, requiring extremely high precision. Industrial-production-use metering rods can reach several meters in length and require a dedicated rod holder for support; they are used in continuous production lines and demand high levels of durability and stability.