How should the following provision in GB7793-2025 be interpreted: "In ordinary classrooms where multimedia teaching is used, each blackboard lighting luminaire shall be equipped with an independent dimming or illuminance-reduction control device."

2025-12-13 · Technical Q&A

First, translate this sentence into what industry people can understand: "In ordinary classrooms using multimedia teaching, each blackboard lighting luminaire shall have an independent dimming or illuminance-reduction control device." This is equivalent to: As long as the classroom uses multimedia (projectors, interactive whiteboards, etc.), the blackboard luminaire is not "optional."

Quick Answer

According to GB 7793-2025, in ordinary classrooms that use multimedia teaching, every blackboard lighting luminaire must have an independent dimming or illuminance-reduction control device. They cannot share a switch across an entire row, and adjustment cannot rely solely on a back-end system.

1. First, translate this sentence into "what industry people can understand"

"For ordinary classrooms using multimedia teaching, each writing board lighting fixture should have an independent dimming or illuminance reduction control device."

Equivalent to:

👉 As long as the classroom uses multimedia (projectors, electronic whiteboards, etc.)
👉 Blackboard lights are not "optional," but rather:

Each one
Must
Be capable of being dimmed or brightened independently (or at least reduce illuminance)

This is no longer a "recommendation," but aClear functional requirement.

2. Item-by-item breakdown (this is what reviewers and inspectors focus on most)

① "Ordinary classrooms using multimedia teaching"

Not just "multimedia classrooms"
Now more than 90% of ordinary classrooms qualify
- Projection
- Electronic whiteboard
- All-in-one machine

👉 The scope of application is very wide, almost full coverage

② "Each blackboard lighting fixture"

This sentenceis very tough, note that it is:

❌ Not "each group"
❌ Not "overall one-button"
✅ It iseach fixture

which means:

left and right blackboard lights
or multiple linear blackboard lights
👉 All must have independent adjustment capability

③ "Independent dimming or illuminance reduction control device"

There are 3 key points here:

✅ 1️⃣ "Independent"

❌ Adjusted together with the classroom lights →Does not count
❌ Cannot be separated from the entire row of blackboard lights →There is risk
✅ At minimum,The writing board system is independent of the ambient lighting

✅ 2️⃣ "Dimming or illuminance reduction"

The standardIs deliberately written very broadly, giving manufacturers and schools flexibility:

✔ Continuous dimming (knob / panel / smart)
✔ Stepped dimming (100% / 70% / 30%)
✔ Switch to "low illuminance mode"

👉 Stepless dimming is not required
👉 But it must be able to "significantly reduce brightness"

✅ 3️⃣ "Control device"

Note:
The emphasis here is on"device", not a software concept.

Generally recognized ones include:

Wall-mounted dimming panel
Independent button
Independent circuit
Intelligent control terminal (provided that on-site operation is possible)

❌ Backend system only, with no on-site operable entry point →High acceptance risk

3. Compared with the 2010 version, where are the changes in this statement?

Item	GB 7793-2010	GB 7793-2025
Whether dimming is mentioned	❌ Not at all	✅ Explicitly proposed
Whiteboard light control	No requirement	Independent dimming/illuminance reduction per luminaire
Multimedia scene	Not considered	Separately listed scene
Degree of mandatory	Functional	Scene function + control function

👉 This is an upgrade from "lighting metrics" to "teaching behavior adaptation"

IV. Why does the standard add this sentence? (The real logic)

There is only one reason:
👉 During projection, if the blackboard light is too bright = glare + unclear visibility + eye damage

Common problems in the past:

As soon as the projector is turned on, the blackboard light is glaring
Teachers can only "turn off the entire row of lights"
The front row is dark, the back row is bright, resulting in extremely poor visibility

This sentence was written specifically to solve this problem.

V. In proposals / bids / products, you can "standardize" the wording as follows

✅ Technical response (highly recommended)

For ordinary classrooms using multimedia teaching, each blackboard lighting fixture in this solution is equipped with an independent dimming or illuminance-reduction control device, which can flexibly adjust brightness according to teaching scenarios such as projection and blackboard writing, complying with the relevant requirements of GB 7793-2025.

✅ Product description (will not be questioned)

Blackboard lighting fixtures support independent dimming/illuminance-reduction control per individual luminaire, meeting the usage needs for brightness adjustment and anti-glare in multimedia teaching scenarios.

VI. Here is an "acceptance pitfall-avoidance reminder" for you (very important)

Under GB 7793-2025,Situations easily rejected:

❌ All blackboard lights share one switch
❌ Only "all on / all off"
❌ Can only be adjusted in the backend system, no on-site operation
❌ Claiming "dimming can be achieved by replacing the luminaires" (not accepted)

More reliable approaches:

✅ Independent circuit for blackboard luminaires
✅ Single luminaire or single side adjustable
✅ Clear dimming / illuminance reduction control on the wall

If you wish, I can next directly help you with:

✔ Breaking this statement into bid scoring points
✔ Writing a standard answer for expert acceptance Q&A
✔ Help you determine whether your current solution counts as "complying with this statement"

Frequently Asked Questions

Our classroom has a projector and an interactive whiteboard. Is it enough to install standard blackboard lights?

No. According to GB 7793-2025, in ordinary classrooms that use multimedia teaching, every blackboard lighting luminaire must have an independent dimming or illuminance-reduction control device so it can be dimmed separately during projection, avoiding glare and poor visibility caused by blackboard lights that are too bright.

Can blackboard lights be controlled by one switch for the whole row?

That does not meet the requirements. The standard emphasizes that every blackboard lighting luminaire must have independent adjustment capability. The left and right blackboard lights, or multiple linear blackboard lights, must all be able to dim or reduce illuminance individually. Having all blackboard lights share one switch is a common reason for failing inspection.

Does dimming have to be stepless? Is stepped dimming acceptable?

Yes. GB 7793-2025 refers to dimming or reducing illuminance. Continuous dimming, stepped dimming (e.g., 100%/70%/30%), or switching to a low-illuminance mode all qualify, but the brightness must be noticeably reduced and the control must be operable on site.

If brightness is only adjusted through a backend system, will it pass acceptance inspection?

The risk is very high. The standard emphasizes control devices and typically recognizes wall-mounted dimming panels, independent buttons, independent circuits, or intelligent control terminals that can be operated on site. If only a backend system is available and there is no operable interface on site, it is likely to be judged as non-compliant.

Compared with the 2010 version, what are the main changes in GB 7793-2025 regarding blackboard lights?

The 2010 version did not mention dimming at all and had no requirements for blackboard light control. The 2025 version explicitly requires independent dimming or illuminance reduction for each luminaire, and separately lists multimedia scenarios, upgrading from lighting metrics to adaptation for teaching activities.