I. Contact roughness meter

1. Accuracy

Typical accuracy: Usually between ±0.01 µm and ±0.1 µm.

Influencing factors: Accuracy is affected by factors such as probe wear, measurement speed, workpiece material hardness and surface condition.

2. Advantages

High accuracy: For surface roughness measurement of hard materials (such as metals), contact instruments usually provide higher accuracy.

Wide application: Applicable to a variety of materials, especially metals and hard materials.

3. Disadvantages
Contact damage: The probe may cause damage to softer materials (such as plastics) during measurement.

Applicability limitations: It may be difficult to achieve for the measurement of complex geometries or tiny structures.

2. Non-contact roughness tester
1. Accuracy
Typical accuracy: usually between ±0.1 µm and ±1 µm, and some high-end devices can reach ±0.01 µm.
Influencing factors: Accuracy is affected by the optical system, surface reflectivity and measurement environment (such as vibration, temperature, etc.).
2. Advantages
Non-destructive measurement: no physical contact with the workpiece surface, suitable for soft or fragile materials.
Widely applicable: can measure surfaces with complex shapes and tiny structures.
3. Disadvantages
Environmental sensitivity: high requirements for light and surface conditions, may be disturbed.
Possible accuracy limitations: in some cases, especially on materials with extremely smooth surfaces, the accuracy may not be as good as contact instruments.

3. Summary
Contact roughness testers generally provide higher accuracy, especially for hard materials, but may cause damage to some materials.
Non-contact roughness testers have more advantages when measuring soft or complex-shaped materials, but their accuracy may be slightly lower than contact instruments.
When choosing a suitable roughness instrument, you should consider the specific measurement needs, material properties and application scenarios.