ICS 27.010  
F 01 
 
 
National Standards of the 
People’s Republic of China  
GB ×××× —×××× 
 
 
Minimum allowable values of energy efficiency and energy 
efficiency grades for Computer Monitors  
(Draft for approval)  
 
 
 
 
Issue Date: XXXX –XX-XX Implemented on: XXXX –XX-XX 
Issued by the General Administration of Quality Supervision, Inspection and 
Quarantine of the People’s Republic of China  
GB ×××× —××××  
Preface  
It should be noted that Clauses 4.2 and 4.4 of this Standard are mandatory, whilst the rest 
are recommended.  
Appendix A to this Standard is a specification appendix.  
This Standard is jointly enacted by the Resources & Environmental Protection Department of 
National Development & Reformation Commission and Industrial Department No 1 of the 
National Standardisation Management Commission.  
This Standard has been prepared and put forward by the  National Energy Foundation & 
Management Standardisation Technical Committee.  
This standard is under the jurisdiction of the National Energy Foundation & Management 
Standardisatio n Technical Committee.  
The units involved in preparing this Standard included China Standardization Institute, China 
Computer Quality Supervision Inspection Centre, the 5th Institute of Message Industrial 
Department, 3M (China) Corp., China Hewlett Packard  Corp., Qinghwa Tongfang Co., Ltd., 
and Philips (China) Investment Corp.  
The main drafters  of this Standard are: Zhang Kuo -Qin, Chen Hai -Hong, Zhou Xing -Hua,  
Song Dan -Mei, Du Guang -Lei, Zhang Xu -Jie, Sun Hui -Fen, Zhang Yu -Qi, and Zhang -Xin.  
Minimum allo wable values of energy efficiency and energy efficiency 
grades for Computer Monitors  
1 Scope  
1.1 This Standard sets the minimum allowable energy efficiency values, energy conservation 
evaluation values, target minimum allowable energy efficiency values, te st methods and 
inspection rules for general purpose computer monitors (hereafter ‘Monitor’).  
1.2 This Standard applies to positive CRT monitoring equipment (hereafter ‘CRT Monitor’) 
used for computers using normal electrical network voltages, and for compu ter monitor 
display equipment with modulator/receivers.  
2 Normative References  
The provisions of the following documents become provisions of this Standard after being 
referenced. For dated reference documents, all later amendments (excluding corrigenda) a nd 
versions do not apply to this Standard; however, the parties to the agreement are encouraged 
to study whether the latest versions of these documents are applicable. For undated reference 
documents, the latest versions apply to this Standard.  
GB 20943 -2007: One -way Output Type AC -DC and AC -Ac external power energy 
efficiency minimum allowable values and energy conservation  evaluation values.  
3   Terms  and Definition  
The following terms and definitions apply to this Standard:  
3.1 Off Mode  
The status in wh ich the Monitor is connected to the power source and the power switch of 
the Monitor is set to “Off”.  
3.2 Energy Efficiency of Computer Monitors  
The ratio value (or Working Efficiency) between the screen illumination intensity of the 
screen and the actual input power of the monitor under the conditions set out in this 
Standard, for which the unit is expressed by “m2nit/W ” or “ cd/W”. 
3.3 Energy Consumption when set to Off Mode  
The active power of the Monitor when in “off” mode, in which “W” expresses the uni t. 3.4 The Minimum Allowable Energy Efficiency values for Computer Monitors  
The minimum energy efficiency that should be achieved by the Monitor under standard testing 
conditions and the maximum active power when set to the “off" mode, for which the unit i s 
expressed by “W”. 
3.5 The Evaluating Values of Energy Conservation for Computer Monitors  
The minimum energy efficiency that should be achieved by energy -saving Monitors when tested 
under the conditions and the maximum active power when set to the “off" m ode, in which “W” 
expresses the unit.  
4 Technical Requirements  
4.1 Monitor Energy Efficiency Grade  
4.1.1  Energy Efficiency Grade  
The energy efficiency of the Monitor shall be divided into three grades, of which the holding 
power is the lowest. The holding power (VA) of each grade of Monitor shall not be lower 
than the requirements listed in Table 1, and the energy consumption when set to “off” shall 
not exceed the requirements set out in Table 1.  
Table 1: Monitor Energy Efficiency Grade  
Energy Efficiency Grade  
Grade 1  Grade 2  Grade 3  
Monitor 
Type  Energy 
Efficiency  
(m2nit/W 
or Cd/W) Energy 
Consumption 
under “off” 
Status  Energy 
Efficiency  
(m2nit/W 
or Cd/W) Energy 
Consumption 
under “off” 
Status  Energy 
Efficiency  
(m2nit/W 
or Cd/W) Energy 
Consumption 
under “o ff” 
Status  
CRT  0.18  0.16 3 0.14 5 
LCD  1.05 0.5 0.85  0.55 2 
4.1.1.1  Calculation for Monitor Unit Time Energy Consumption Value  
Under certain working modes, the unit time energy consumption value ( Pi) of the Monitor 
shall be calculated according to Fo rmula (1):  
tEtPi= ................................ ............................ 1Ž 
Where 
Pi - The unit time energy consumption value of the Monitor, in which “W” expresses the unit. 
Et - Actual measured energy consumption, in which “W/h” expresses the unit.  
t - Actual measured continuing time, in whic h “h” expresses the unit.  
4.1.1.2  Calculation for Monitor Energy Efficiency  
The energy efficiency (Eff) of the Monitor shall be calculated by Formula (2):  
PwLSEff×= ................................ ....................... 2Ž 
Where 
Eff - Energy efficiency, in which “cd/W” expresses the unit . 
Pw - Unit time energy consumption value of the Monitor working mode, in which “W” 
expresses the unit.  
S - Screen size of the Monitor, in which “W” expresses the unit.  
L - Actually measures brightness of the Monitor screen,  in which “cd/  m2” expresses the 
unit. 
 
4.2 Energy Efficiency Minimum AllowableValues  
The energy efficiency minimum allowable value shall be Grade 3 in energy efficiency 
grade.  
4.3 Energy conservation Evaluation Value  
The energy conservation evaluation value shall be Grade 2 of the energy efficien cy grade.  
If the Monitor uses an external power source, then such power shall meet the requirements 
set out in Clause 3.2 of GB 20943 -2007.  
4.4 Target Minimum Allowable Energy Efficiency Value  
The target minimum allowable energy efficiency value shall be G rade 2 energy efficiency 
three years following the day on which this Standard is implemented.  
5 Test Method  
The screen size, brightness, working mode, energy consumption and “off” mode will be 
tested according to the test method specified in Appendix A.  
6 Insp ection Rules  6.1 Ex-Factory Inspection  
6.1.1  The minimum allowable energy efficiency value shall be indicated in the ex -factory 
inspection of the Monitor, and the sampling method shall be determined by the Production 
Industrial Quality Inspection Departmen t. 
6.1.2  If the inspection results indicate that the minimum allowable energy efficiency value fails to 
meet the requirements set out in Clauses 4.2 and 4.4 of this Standard, then it shall be 
prevented from being shipped out of the factory.  
6.2 Type Inspec tion 
6.2.1  If any of the following happens to the Monitor, then a type inspection for the minimum 
allowable energy efficiency value shall be carried out:  
a) if new items are added after the pilot run;  
b) if the product design changes, or if the workmanship or  materials used have noticeably 
affected the performance;  
c) when production is restored following more than one year of downtime;  
d) when an inspection is required by the Quality & Technical Supervision Department.  
6.2.2  Sampling Program for the Type Inspect ion 
During the type inspection, one unit shall be selected for each batch. If the minimum 
allowable energy efficiency value of the selected sample fails to meet the requirements set 
out in this Standard, then a further two units shall be selected from the same batch for 
inspection. If these units pass the inspection, then the products of the same batch shall be 
deemed to meet the Standard; however, if one of the units still fails to meet the requirements, 
then all the products from that batch shall be deeme d as having failed to meet the Standard.   
Appendix A  
(Standardised Appendix)  
Test Method for Monitor Energy Efficiency and Energy Consumption when in Shutdown 
Mode  
A.1 Test Conditions  
The test environment shall be as follows: room temperature, 15  ~35 ; relative humidity, 
45%~75%; atmospheric pressure, 86~106 kPa; test power source, AC voltage 220 ±5V; and 
frequency, 50±0.5 Hz. 
A.2 Test Instrument Accuracy  
The total harmonic distortion of the test power must not exceed 3% and resistance shall be 
below 0.25 o hm. The WH Meter shall be able to test for energy consumption at a level of 
below 20mW, and the unit shall be W/h.  
When the Power Gauge shows 1W of active power, accuracy shall be expressed within 
0.1W and the Peak Factor of the current below 2A shall be l ess than 5.  
A.3 Test Method  
A.3.1  Test Setup  
a) Dark Room Conditions: disconnect the power of the Monitor and place the optical 
measuring device vertically at the centre of the screen. The measured illumination value of 
the Monitor shall not exceed 10Lx.  
b) Colour Control and Peripheral Equipment: All colour control functions (hue and saturation, 
etc.) should be adjusted to factory saving values and should not be connected to any 
external equipment, including USB Hubs or Ports. The adjustable built -in Ampli fier and 
TV Tuner, etc. shall be adjusted to the minimum level of energy consumption.  
c) Scanning Frequency: when under 75Hz of scanning frequency, the pixel type of the CRT 
shall present the preferred pixel type to be the maximum resolution. As for the LC D and 
other monitors using conventional pixel technology, the pixel type shall be set to a constant 
level. The scanning frequency of the LCD shall be set to 60Hz or at a different frequency 
as recommended by the manufacturer.  
d) Monitor Image Dimension, Brigh tness and Contrast Setup:  
The non -homogeneity brightness index of the Monitor brightness shall meet the 
requirements set out in SJ/T 11292 and shall be tested under the following setup modes:  
Monitor Brightness  Contrast  Test Picture  Type  
CRT  Meet the Setu p 
Status 1 
requirements.  Meet the Setup 
Status 1 
requirements.  Taking 80% of 
white zone in the 
picture (Fig. A1).  
LCD  Meet the Setup 
Status 2 
requirements.  Meet the Setup 
Status 2 
requirements.  Taking 80% of 
white zone in the 
picture (Fig. A1).  
Setup Mod e 1: For CRT Monitors, set the monitor to the image dimensions recommended 
by the manufacturer (such dimensions shall normally be slightly smaller than the maximum 
visible screen size), and then set the brightness and contrast levels to maximum. Display a 
full black to full white image for providing an 8 -class grey level test image (Fig. A2). Firstly, 
adjust the “Bright” for appropriately identifying 0% and 5% grey level in the first row and 
then diminishing the “Contrast” from the maximum value to 100% and  95% grey levels in 
the second row can be appropriately identified with each other.  
Setup Mode 2 : For LCD Monitors, display a full black to full white image for providing 
8-class grey level test image (Fig. A2). When the maximum brightness and contrast lev els 
are reached, two grey levels of 0% and 5% in the first row should be distinguished; if this is 
not, adjust the contrast until distinguishable.   
 
Fig. 1: The white block image taking up 80% of the picture.  
 
Fig. 2: 8 -class Gray Level  
e) Under dark  room conditions, place the optical measuring device vertically at the centre of 
the screen to carry out the measuring. The measured screen size shall cover at least 500 
pixels. Under no circumstances should the illuminated size be smaller than the size sc anned 
by the measuring device.  
A.3.2  Energy Efficiency Test Method  
a) Connect the test sample to the power and testing equipment.  
b) Connect the power to all pieces of testing equipment and adjust the voltage and frequency to 
the appropriate levels.  
c) Check the working mode of the test sample, as per A.3.1.b . 
 Black  
White  
Black   
d) Set the appropriate scanning frequency, as per A.3.1.c.  
e) Set the test sample under the desired working type and then maintain stability for over 20 
minutes.  
f) Confirm that the size, brightness and contrast meet the test requirements, as per A.3.1.d.  
g) Test the brightness at the centre of the sample screen and then also test the screen size.  
h) Test the energy consumption of the sample: the test time should not be less than 10 
minutes.  
i) Register the test c onditions and test figures.  
A.3.3  Energy Consumption Test Method When Set to “Off” Mode:  
a) Connect the power to all pieces of test equipment and adjust the voltage and frequency to 
the appropriate levels.  
b) Maintain the Monitor at “off” until the measured powe r reading stabilises.  
c) Test the energy consumption of the sample: the test time should not be less than 10 minutes.  
d) Register the test conditions and test figures.