Verification of Basic Markings
Mandatory Certification Check: Legitimate products compliant with national standards must bear a clear CCC certification mark. They must also clearly display the rated voltage, rated current, applicable standard (e.g., GB/T 2099.1), and manufacturer details. Immediately reject products with blurry printing or missing specifications (so-called "three-no" products).
Wire Gauge Matching:Verify the conductor specifications against the load power. Standard 10A appliances require a conductor cross-section of at least 0.75mm², while high-power 16A appliances require at least 1.0mm². For a given length, a heavier cord that feels substantial usually indicates a higher copper content.
Preliminary Screening of Appearance and Feel
Sheath Material Assessment: High-quality cords typically use matte-finish TPE or eco-friendly PVC and have almost no pungent odor. Inferior cords often have a glossy sheath with a strong chemical smell; they tend to harden and become brittle in low temperatures, showing white stress marks or cracking after just a few bends.
Plug Construction Check: High-quality plugs are molded as a single unit with no burrs and minimal seams; the prongs are made of nickel-plated brass and are straight and secure. Inferior products have loose prongs and lack reinforced strain relief at the connection point between the plug and the cord, making the internal wires prone to exposure when pulled.
Quick Practical Verification
Conductor Authenticity Check: Cut the end of the cord to examine the cross-section. Pure copper wire appears uniformly purplish-red with a metallic luster. Iron-core or copper-clad iron wires appear grayish-white; they are strongly attracted to neodymium magnets and will snap or flake off after being bent repeatedly.
Mechanical Strength Test: Hold the cord at the base of the plug and bend it back and forth 10 times; high-quality cords will not crack. Use a spring scale to hook...
