GB 32028-2015Minimum Allowable Values of Energy Efficiency and Energy Efficiency Grades for Projectors (English PDF)

4.2 Minimum allowable values of passive standby power for projectors

The passive standby power of projectors shall be less than or equal to 0.50 W.

The passive standby power is rounded according to GB/T 8170, retaining two digits after the decimal point.

4.3 Minimum allowable values of energy efficiency for projectors

The minimum projection efficiency that is required by the minimum allowable values of energy efficiency for projectors is grade-3 of energy efficiency grades in Table 1, which shall meet the requirements of minimum allowable values of passive standby power at the same time.

For projectors that use an external power supply, the external power supply that is used shall meet the requirements of minimum allowable values in GB 20943.

4.4 Evaluating values of energy conservation for projectors

The minimum projection efficiency that is required by the evaluating values of energy conservation for projectors is grade-2 of energy efficiency grades in

Table 1, which shall meet the requirements of minimum allowable values of passive standby power at the same time.

For projectors that use an external power supply, the external power supply that is used shall meet the requirements of evaluating values of energy conservation in GB 20943.

A.1 Measurement conditions

A.1.1 Environmental conditions

Measurements shall be performed under the following conditions of temperature, humidity and pressure:

-- Temperature: 15°C ~ 25°C;

-- Relative humidity: 25% ~ 75%;

-- Atmospheric pressure: 86 kPa ~ 106 kPa.

A.1.2 Power supply

-- Power supply voltage: AC 220 V ± 4 V;

-- Power supply frequency: 50 Hz ± 1 Hz;

-- Total harmonic distortion: <= 2%.

A.1.3 Test site

Measurements shall be performed in a dark room with a stray illuminance less than or equal to 1 lx.

A.2 Measurement instruments

A.2.1 Illuminance meter:

-- Illuminance measurement range: 1 lx ~ 30 000 lx;

-- Illuminance measurement accuracy: ±4%;

-- Chromaticity measurement resolution: ±0.002.

A.2.2 Colorimeter:

The colorimeter measurement accuracy is ±0.002.

A.2.3 Power meter:

signal can be clearly distinguished. The adjustment method of the limit eight gray signal is as follows:

By adjusting the "brightness" and "contrast" settings of the projector, adjust the display to a state that the difference between the gray scale patches of limit black and white can be just distinguished by human eyes.

First, adjust the "brightness" setting, so that the two extreme black gray scales of 0% and 5% in the first row can be just distinguished. Then, gradually reduce the "contrast" from the maximum value, until the two extreme white gray scales of 100% and 95% of gray scales in the second row can be just distinguished from each other.

Repeat the above processes, until the requirements that the two types of limit gray scales are exactly distinguished can be achieved simultaneously.

If the limit black gray scale can be just distinguished, and the 100% and 95% white gray scales are always indistinguishable when adjusting the “contrast”;

then, adjust the “contrast” until the two white gray scales of 95% and 90% gray can be just distinguished.

If the limit white gray scale can be just distinguished, and the 0% and 5% black gray scales are always indistinguishable when adjusting the “brightness”; then, adjust the “brightness” until the two black gray scales of 5% and 10% gray can be just distinguished.

If the 0%, 5% black gray scales, and the 95%, 100% white gray scales cannot reach the limit resolution; then, in the case of ensuring the largest number of gray scales, adjust to the largest number of white gray scales, and indicate in the report.

If the 100% and 95% white gray scales are always legible, set the “contrast” to the middle.

If the 0% and 5% black gray scales are always legible, set the “brightness” to the middle.

Throughout the adjustment process, the difference between the four blocks of

10%, 15%, 85% and 90% can be distinguished to avoid dizziness and be used as the reference of brightness difference (when adjusting the difference between the limit black and white blocks, the difference of other gray blocks may not be uniform).

A.4.2.5 Record product parameters such as the projector's light source type, working mode, number of bulbs, display device type, used lens specifications;

and record the set states of parameters such as image mode, brightness, contrast and color temperature.

Appendix B (Normative)

Test method of passive standby power for projectors

B.1 Measurement conditions

B.1.1 Environmental conditions

Same as A.1.1.

B.1.2 Power supply

Same as A.1.2.

B.2 Measurement instruments

Same as A.2.

B.3 Test procedure of passive standby power

B.3.1 Turn on the power of all test equipment; adjust the working range correctly to connect the projector to the test equipment.

B.3.2 Adjust the projector from the working state to the passive standby mode.

B.3.3 After 10 minutes in the passive standby mode, use a power meter with the power averaging function to monitor for 5 min; the measured average power is the passive standby power; or use a watt-hour meter (or a power meter with digital integral function) to monitor for 5 min (guarantee that more than 200 times of sampling are taken during the integral time); calculate the passive standby power according to Formula (B.1):

Where:

Pd -- passive standby power, in watts (W), accurate to 0.01 W;

Ed -- measured power consumption in passive standby mode, in watt hours (W·h);

Td -- measurement time of passive standby mode, in hours (h).

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