GB 21520-2015 Energy Efficiency Limit Values and Energy Efficiency Grades Test Report for Computer Monitors Application

Computer Monitor Energy Efficiency Test GB 21520-2015 Technical Requirements:

1. Computer Monitor Energy Efficiency Rating

The display energy efficiency is divided into 3 levels, with Level 1 having the highest efficiency. The energy efficiency of each level of display should not be less than that specified in Table 1. The energy efficiency should be rounded according to the relevant provisions of GB/T8170, retaining two significant figures, and the rounded value should not be less than that specified in Table 1.

2. Display Energy Efficiency Limit

The display requires a lower energy efficiency value, corresponding to Level 3 in Table 1's energy efficiency ratings, while also meeting the requirements for power consumption in the off state and sleep state. For displays using an external power supply, the external power supply must comply with the mandatory requirements of GB20943.

3. Display Energy Rating

The display energy-saving evaluation requires a lower energy efficiency index, which is two levels lower than the energy efficiency grade in Table 1, while also meeting the requirements for sleep mode power and shutdown power. For displays using an external power supply, the external power supply used must comply with the mandatory requirements of GB20943.

4. Display Sleep Mode Power and Shutdown Power Limit Values

The power consumption in shutdown and sleep modes should be rounded in accordance with the relevant provisions of GB/T8170, retaining two decimal places. The rounded values for standard display shutdown and sleep modes should be less than or equal to 0.50W. For high-performance displays, the rounded values for shutdown and sleep modes should be less than or equal to 0.50W and 1.2W, respectively.

GB 21520-2015 Energy Efficiency Measurement Test Setup

Including:

a) Darkroom Conditions: Measurements should be conducted in a darkroom, with the scattered illuminance on the display surface not exceeding or equal to 1.01x, i.e., the screen illuminance is not exceeding or equal to 1.0lx when the display is in the off mode.

b) Color Control and Peripherals: All color controls (hue, saturation, etc.) should be adjusted to the factory default settings. No external devices, including USB hubs or ports, should be connected.

c) Additional Features: Ensure additional features are turned off. If not feasible, adjust to the position of minimum energy consumption and note this in the report.

d) Refresh Rate: Set to 60Hz or the manufacturer-recommended refresh rate.

e) Display Status Settings:

Restore the monitor to factory settings. If the monitor has an ambient light control function, disable it. If it cannot be disabled, to ensure the smooth progress of display performance measurement, provide no less than 3001 lux at the light sensor and note this in the report.

Enter the white window test signal shown in Figure A.1 with inherent resolution matching the display, and preheat for at least 30 minutes.

Enter the 8-level grayscale test signal as shown in Figure A.2. Adjust the "Contrast" and "Brightness" controls to the higher position. If the second row and the 95% grayscale levels can be distinguished, this is the test state. If they cannot be differentiated, reduce the contrast until they can be just distinguished. If the 95% and 90% grayscale levels cannot be distinguished at all, reduce the "Contrast" until the two white levels at 95% and 90% grayscale can be just distinguished. If the 95% and 90% white levels cannot be distinguished at all, reduce the "Contrast" until the two white levels at 90% and 85% grayscale can be just distinguished. If the 90% and 85% white levels cannot be distinguished at all, reduce the "Contrast" to the minimum position.