GB/T 15717-2021 in English

Core changes in the standard revision

Key technical requirements of the test device

The core components of the measuring device include: DC bridge (accuracy ±1%), copper measuring head (thickness 10mm), rubber sheet (Shore A hardness 70-80). Non-copper measuring heads must be specially noted in the report.

Specimen preparation specifications

• Dimension requirements: length ≥140mm, width 100±0.1mm (if less than 100mm, follow the actual requirements)
• Surface quality: no defects such as coating shedding, creases, sputtering points, etc.
• Environmental adjustment: balance for 4 hours at 23±3℃/50±10%RH environment

Resistance measurement principle

Based on Ohm's law, the thickness is converted by measuring the block resistance (Ω/□):

d=ρ/(Ω/□) (ρ is the resistivity after temperature correction)

Appendix A provides the correction curve of copper/aluminum resistivity changing with temperature (21-25℃ data).

Implementation suggestions

1. The measuring head must be cleaned with anhydrous ethanol before measurement
2. Each sample should be measured 20mm away from the edge along the length direction
3. Non-copper measuring head data must be separately databased
4. Regularly check the spacing accuracy between the two measuring heads (±0.1mm)