The judgment standard of the GB21456 low carbon steel standard pots strictly follows the appendix requirements of GB 21456-2024 "Minimum Allowable Values of Energy Efficiency and Energy Efficiency Grades for Household Induction Cookers". It mainly judges from four core dimensions: material, size, appearance and performance. Only when all requirements are met can it be used as a qualified test tool for energy efficiency testing.

(I) Material Judgment Standard

1. The pot body and lid must be made of Q235 low-carbon steel. The mass fraction of carbon is strictly controlled within 0.08%. It ensures that the electrical conductivity and magnetic permeability of the material meet the test requirements. It avoids unstable heat conduction efficiency caused by excessive material impurities and excessive carbon content.

2. The material must undergo strict physical and chemical testing. It has no obvious impurities, cracks, pores and other defects. It ensures material uniformity. It avoids heat conduction impact caused by local material differences. A material qualification certificate must be provided during testing.

(II) Size Judgment Standard

Size is the core indicator for the judgment of standard steel pots. Standard steel pots of different models (B1 ~ B4) must strictly meet the following size requirements (unit: mm). The deviation must be controlled within the range allowed by the standard:

1. Model B1: caliber 140, bottom diameter 120, pot height 75, pot thickness 1.5, capacity 1L;

2. Model B2: caliber 200, bottom diameter 180, pot height 95, pot thickness 1.5, capacity 3L;

3. Model B3: caliber 220, bottom diameter 200, pot height 110, pot thickness 1.5, capacity 4L;

4. Model B4: caliber 280, bottom diameter 260, pot height 105, pot thickness 2.0, capacity 6L;

5. The thickness of the lid is uniformly 1mm, and it must have a through hole with a diameter of 10mm. The size deviation does not exceed ±0.5mm. The maximum concavity of the pot bottom does not exceed 0.6% of the effective diameter. It is not allowed to bulge outward. The side of the pot body must clearly mark the bottom effective diameter.

(III) Appearance Judgment Standard

1. The surface of the pot body and lid must be smooth. It has no burrs, scratches, rust, deformation and other defects. The surface is treated with sanding and rust prevention. It ensures that the surface roughness meets the standard requirements. It avoids heat conduction and appearance integrity impact caused by surface defects.

2. The connection between the pot body and the lid must be flat and firm. It has no looseness or gaps. It avoids heat loss from the connection during heating, which affects the test accuracy. The marks are clear and standardized. The marked model, size and other information are complete and accurate.

(IV) Performance Judgment Standard

1. Heat conduction performance: Under standard test conditions, the pot body conducts heat uniformly. It has no local overheating or heat conduction lag. During heating, heat can be quickly and uniformly transferred to the medium in the pot. It meets the conduction requirements of thermal efficiency testing.

2. Stability: Under rated power heating conditions, the pot body has no obvious deformation or damage. The surface temperature distribution is uniform. It will not cause material performance changes due to high temperature. It ensures the consistency of repeated tests.

3. Adaptability: It can be closely attached to the induction cooker panel. It is suitable for induction cooker heating units of different power levels. During heating, there is no obvious shaking or sliding. It ensures the stability of electromagnetic induction. It avoids heat loss caused by poor fit.