Material: High-transparency PET
This product features fine craftsmanship, with excellent colorfastness, durability, and clear dots, lines and circles. Material thickness: 0.1mm.

Function of Dot & Line Gauges

Quality inspection uses dot & line gauge diagrams to help inspectors standardize criteria.
Dot gauges (including various sizes, stain cards) are mainly used by quality control departments to assess stains. They measure and compare the area, diameter, width, length and gray level of dots/scratches on components such as phone casings, LENS and DISPLAY, to determine whether an irregular dot or line scratch meets inspection requirements.
By specifying appearance grades, dot & line gauge cards are used for objective quantitative assessment. This unifies the product appearance evaluation standards across the company, reduces judgment differences between parts receiving departments and suppliers, and enables accurate communication of required product appearance to suppliers and receiving departments—without the need to make sample limits or specify appearance grades.

Usage of Dot & Line Gauges

When encountering an irregular dot:
  1. First determine its approximate size, and find a roughly matching dot on the gauge.
  2. Identify the shape of the irregular dot, then locate the row on the gauge with similar-sized dots, and select the one with a similar shape.
  3. Overlay the gauge on the dot. If the dot is fully covered, check if its size meets the allowable standard—if yes, it passes; if no, it fails.
When unsure whether a linear scratch meets the standard:
Overlay the 25% gray area of the gauge on the scratch. If the scratch is invisible and its length is shorter than the specified limit, it passes; otherwise, it fails.

Composition of Dot Gauges

Dot gauges are usually A4-sized, consisting of: