TOOLS
Analizator osvjetljenja i ujednačenosti
Record your lux readings. Find the dark spots. Keep a report you can check.
Your survey
Room or area
m
ft
m
ft
Duljina
Width
Grid columns
Grid rows
Height (m)
6 columns × 4 rows · 24 centre points · Spacing 1.333 × 1.5 m
Compare with your targets (optional)
Average ≥ (lx)
Uniformity ≥
U₀ = minimum ÷ average. Comparison uses entered values; measurement uncertainty is not assessed.
Understanding uniformity
Illuminance tells you how bright a surface is on average; uniformity tells you how evenly that light is spread. A room can meet its average target yet still have dark corners that are uncomfortable or unsafe. Uniformity is the ratio between the darkest measured point and the overall average (U₀), and is also expressed as minimum over maximum (U₁).
U₀ = minimum illuminance ÷ average illuminance · U₁ = minimum ÷ maximum
Why it matters
Poor uniformity means hot spots and dark patches. In offices and classrooms it causes eye strain; in circulation and emergency areas it is a safety issue.
How to measure
Divide the area into a grid of centre points, hold the sensor at a set height (commonly the work plane) and record each point without shading the sensor.
Average vs uniformity
Average can pass while uniformity fails. A few bright fixtures push the average up but leave the darkest point far below, dragging U₀ down.
What the targets mean
Typical recommendations are an average and a minimum uniformity (for example U₀ ≥ 0.6). Standards such as EN 12464 define levels per task.
Worked example: minimum 255 lx ÷ average 522.2 lx = U₀ 0.488 – below a 0.6 target even though the average passes.
Your measurements
MEASURED POINTS
24 / 24 recorded
Prosjek 522.2 lx · Target ≥ 500 lx
Prosjek
522.2 lx
Minimum
255 lx
Maximum
582 lx
Uniformity U₀
0.488
Min / max
0.438
Average: meets target
Uniformity: check
Uniformity: check
low
high
Schematic, not to scale
high
Schematic, not to scale
SELECTED POINT – A1
Enter saves and follows a snake path across the rows. Blank stays unmeasured.
Example · not yet saved
Good to know
Where should I take the readings?
At the centre points of an evenly spaced grid across the room, at the height of the work plane or the level your project specifies. Keep the sensor horizontal, hold it away from your body and avoid casting your own shadow on it.
Why can the average be enough, but uniformity too low?
The average is pulled up by the bright fixtures while one dark spot stays far below. Uniformity U₀ = minimum ÷ average catches exactly that single weak point, so it fails even though the mean passes.
What do the two uniformity ratios mean?
U₀ = minimum ÷ average is the value most standards use. U₁ = minimum ÷ maximum is a stricter worst-case ratio. The analyzer shows both so you can compare against the requirement in your spec.
What if a point is missing or reads zero?
A zero is treated as an unmeasured blank and excluded from the statistics. If a real point genuinely reads near zero, that is a serious dark spot – mark it as a note and investigate before accepting the survey.
Can this page measure light with my phone?
No. The analyzer only processes lux readings you enter from a calibrated lux meter. Phone light sensors are not calibrated and should not be used for a compliance measurement.
How do I keep a record or work without internet?
Use Download CSV to export the readings and Copy results for a text summary. Save / report keeps an offline copy in this browser so you can reopen the survey later.
Keep the measurements with your project details when discussing the installation.
Saznajte više stručnih predavanja koje vam manje ljudi govori prije nego što pogriješite.