🌿 Illuminance and uniformity of electric lighting at workplaces
In short
Measurement of the illuminance with a luxmeter at the points of a grid on the working plane (the task area, the immediate surrounding area, the background area, the circulation areas), determination of the average illuminance Eavg and of the uniformity U0 = Emin/Eavg and comparison with the maintained illuminance required by PN-EN 12464-1. The test is performed according to PN-E-04040-03:1983; Quantities determined: Eavg [lx] (to the nearest whole number) and U0 = Emin/Eavg (to two decimal places), with expanded uncertainty k = 2. The procedure comprises 6 steps; it is used for: Periodic measurements of the lighting at workplaces for the purposes of occupational health and safety — offices, production halls, warehouses, laboratories, medical and educational establishments, Acceptance of new and modernised lighting installations — comparison with the design made in accordance with PN-EN 12464-1, Assessment of workplaces with combined lighting (general + local) and of workplaces with monitors.
At a glance
- Standard: PN-E-04040-03:1983
- Category: Environment
- Procedure steps: 6
- Quantities determined: Eavg [lx] (to the nearest whole number) and U0 = Emin/Eavg (to two decimal places), with expanded uncertainty k = 2
- Measurement grid: points at the centres of the cells; a cell with a ratio of the sides of 0.5–2; p = 0.2·5^log(d); a band of 0.5 m at the walls excluded; not under the luminaires
- Working plane: 0.85 m above the floor (tables, machine tools); the floor (corridors, sanitary rooms, open ground)
Overview
Status of the standard: PN-E-04040-03:1983 (the former designation PN-83/E-04040/03) was withdrawn by PKN on 5 September 2014, with no replacing standard indicated (status of the PKN card as of 23.09.2026), but it is still invoked in the accreditation scopes of laboratories.
The standard PN-83/E-04040/03 describes the technique of the photometric measurement of illuminance, including the location of the measurement points on working planes (clause 2.7.1.3). Measurements of the illuminance and of the uniformity of the electric lighting at workplaces are carried out in accordance with that standard, and the results are assessed in accordance with the requirements of PN-EN 12464-1 "Light and lighting — Lighting of work places — Part 1: Indoor work places" (the current edition PN-EN 12464-1:2022-01, based on EN 12464-1:2021, replaced PN-EN 12464-1:2012; earlier the edition of 2004) and PN-EN 12464-2 for outdoor work places. Until 2004 the requirements and the methodology were given by the standard PN-84/E-02033 "Interior lighting with electric light" (now withdrawn), from which the concept of the working plane and the principles of the choice of the number of points are still drawn.
PN-EN 12464-1 lays down the lighting requirements for people at indoor work places as regards comfort and visual performance: all the values of illuminance in the standard are maintained values, below which the average illuminance in the given area may not fall; for the calculation and the measurement of the average illuminance and of the uniformity the grid of points defined in the standard is used (clause 5.4). The standard gives no guidance as to the methodology of the measurements themselves — the measurements should be made by persons with a knowledge of lighting technique and of the photometric measurements described in PN-83/E-04040.03 and PN-89/E-04040.00. Periodic measurements of the lighting follow from the occupational health and safety provisions; the regulation on general provisions on occupational health and safety requires in addition that the ratio of the average illuminances in adjoining rooms through which circulation takes place should not be greater than 5:1.
THE SCALE OF CITATIONS AND A CORRECTION OF THE KEY (23.09.2026). The search key had the form "PN-E-04040-03" and showed 8 entries at 5 laboratories. The scopes write this standard differently: "PN-83/E-04040.03" 223 times, "PN-83/E-04040/03" 13, "PN-83/E-04040-03" 10, "PN-83/E-04040.3" 2, and in the new scheme "PN-E-04040-03:1983" only 6. After the key was changed to "PN-83/E-04040" the tab shows 247 entries at 112 laboratories. Checked before the change: only sheet 03 stands under this prefix, so the key does not pull in other sheets of the E-04040 series. Six records in the new scheme remain outside the matching — that is the price of choosing one generation of the record.
Method principle
The illuminance E [lx] is measured with a luxmeter with a silicon photocell of a spectral sensitivity matched to the curve of sensitivity of the eye V(λ) for photopic vision and with an angular correction to the cosine curve (part of the flux reflected from the walls falls on the cell at a large angle and without the correction would give a systematic error). The head is placed on the working plane — horizontal at a height of 0.85 m in interiors with tables and machine tools, at the level of the floor in corridors, staircases and sanitary rooms, vertical or inclined where the visual task is so set (racks, control desks). The measurement points lie at the centres of the cells of the lighting grid; the cells close to a square (ratio of the sides 0.5–2), and their maximum dimension p = 0.2·5^log(d), where d — the longer dimension of the area in m (the shorter one where the ratio of the sides is ≥ 2). From the readings Eavg = (E1 + … + Ek)/k and the uniformity U0 = Emin/Eavg are calculated and compared with the maintained illuminance and with the uniformity required for the given task.
Applications
- Periodic measurements of the lighting at workplaces for the purposes of occupational health and safety — offices, production halls, warehouses, laboratories, medical and educational establishments
- Acceptance of new and modernised lighting installations — comparison with the design made in accordance with PN-EN 12464-1
- Assessment of workplaces with combined lighting (general + local) and of workplaces with monitors
- Checking of the ratio of the illuminances in adjoining rooms (≤ 5:1) and of the lighting of the circulation areas
- Measurements on racks and shelves (a vertical plane) and on control desks
Key parameters
| Parameter | Value |
|---|---|
| Quantities determined | Eavg [lx] (to the nearest whole number) and U0 = Emin/Eavg (to two decimal places), with expanded uncertainty k = 2 |
| Measurement grid | points at the centres of the cells; a cell with a ratio of the sides of 0.5–2; p = 0.2·5^log(d); a band of 0.5 m at the walls excluded; not under the luminaires |
| Working plane | 0.85 m above the floor (tables, machine tools); the floor (corridors, sanitary rooms, open ground) |
| Areas according to PN-EN 12464-1 | the task area; the immediate surrounding area (a band of ≥ 0.5 m); the background area (a band of ≥ 3 m); small objects — at least 3 points |
| Conditions | after dusk; discharge lamps switched on ≥ 30 min; new lamps burned in ≥ 100 h; dark clothing; check of the luxmeter with a calibrator (deviation ≤ 3 lx) |
| Scale of illuminances (EN 12665) | 5 – 7.5 – 10 – 15 – 20 – 30 – 50 – 75 – 100 – 150 – 200 – 300 – 500 – 750 – 1000 – … lx |
Standard
- Standard number
- PN-E-04040-03:1983
- Title (PL)
- Pomiary fotometryczne i radiometryczne — Pomiar natężenia oświetlenia
- Title (EN)
- Photometric and radiometric measurements — Measurement of illuminance
Step-by-step procedure
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Inspection and preparation
Note the type of light sources, the type and the arrangement of the luminaires, the power, the degree of soiling, the number of lamps in working order and out of order and the type of lighting (general, local, combined). The measurements are not carried out where a considerable part of the lamps is not lit (the literature gives a threshold of 10–20 %). Measure the temperature and the humidity. New installations: the lamps burned in for at least 100 h (discharge lamps).
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Conditions of measurement
Carry out the measurements after nightfall, without any contribution of daylight; switch on the discharge lamps at least 30 min beforehand (incandescent and halogen lamps may be measured at once). As far as possible check the supply voltage. The person measuring in dark clothing; check the luxmeter with the calibrator.
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Determination of the planes and the areas
At each workplace establish the working plane (horizontal 0.85 m, the floor or vertical/inclined), distinguish the task area (on the basis of observation of the activities or — where it is unknown — the whole plane), the band of the immediate surrounding area (≥ 0.5 m) and the background area (≥ 3 m). In rooms without distinct working planes and with uniform general lighting — a grid over the whole plan at a height of 0.85 m; in the circulation areas — on the floor, in a grid with a side of about 1 m.
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Grid of points
Divide the area into cells close to a square (ratio of the sides 0.5–2) of a dimension not greater than p = 0.2·5^log(d); the points at the centres of the cells, not under the luminaires, with the exclusion of the band of 0.5 m at the walls (unless the task area lies within that band). Small objects (pressure gauges, control desks) — at least 3 points; racks — on a vertical plane at the lowest and at the highest shelf.
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Measurement
Place the head so that its active plane coincides with the plane of measurement; take the readings without obscuring the head or the luminaires (obscuring lowers the reading by as much as 30–40 %). At each point one measurement. Examination of the circulation areas and post-completion examination of the general lighting — with the local lighting switched off; assessment of the visual task — with the general and the local lighting switched on.
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Calculations and assessment
Calculate Eavg = ΣEi/k and U0 = Emin/Eavg separately for the task area, the immediate surrounding area, the background area and the circulation areas. Compare Eavg with the maintained illuminance from PN-EN 12464-1 (increased where the visual work is critical, the details small or of low contrast, the task of long duration), and U0 with the required uniformity. For a new installation compare the initial value multiplied by the maintenance factor from the design. Check the ratio of Eavg of adjoining rooms (≤ 5:1) and the share of the general lighting in the combined lighting (≥ 20 %). After the measurements check the luxmeter again.
Required equipment and apparatus
| Equipment | Example | Indicative price |
|---|---|---|
| Luxmeter | with a silicon photocell of a spectral characteristic matched to V(λ) and with cosine correction; with a valid calibration certificate (e.g. Sonopan L-100) | — |
| Photometric calibrator | for checking the luxmeter before and after the measurements | — |
| Thermo-hygrometer | control of the environmental conditions within the operating limits of the luxmeter | — |
| Measuring tape or rangefinder | the dimensions of the room and of the areas for determining the grid | — |
| Plan of the room and record sheet | a sketch of the arrangement of the luminaires, the workplaces and the measurement points; a record of the type of lamps and luminaires and of the number of lamps out of order | — |
Health and safety (OHS)
- Measurements after dusk with full lighting — in production halls agree access to the workplaces and the machines with the user
- Do not touch the luminaires and the light sources; checking of the working order of the lamps only visually
- Protect the photocell of the luxmeter against soiling and scratching — this changes its characteristics
Frequently asked questions
Which standard describes this test?
The test is performed according to PN-E-04040-03:1983 — “Photometric and radiometric measurements — Measurement of illuminance”.
How does this method work?
The illuminance E [lx] is measured with a luxmeter with a silicon photocell of a spectral sensitivity matched to the curve of sensitivity of the eye V(λ) for photopic vision and with an angular correction to the cosine curve (part of the flux reflected from the walls falls on the cell at a large angle and without the correction would give a systematic error). The head is placed on the working plane — horizontal at a height of 0.
What is the measuring range and accuracy?
Quantities determined: Eavg [lx] (to the nearest whole number) and U0 = Emin/Eavg (to two decimal places), with expanded uncertainty k = 2; Measurement grid: points at the centres of the cells; a cell with a ratio of the sides of 0.5–2; p = 0.2·5^log(d); a band of 0.5 m at the walls excluded; not under the luminaires; Working plane: 0.85 m above the floor (tables, machine tools); the floor (corridors, sanitary rooms, open ground); Areas according to PN-EN 12464-1: the task area; the immediate surrounding area (a band of ≥ 0.5 m); the background area (a band of ≥ 3 m); small objects — at least 3 points.
How long does the test take?
The procedure comprises 6 steps. The standard does not give a duration for every stage — the laboratory's own procedure decides.
What equipment is required?
Luxmeter, Photometric calibrator, Thermo-hygrometer, Measuring tape or rangefinder, Plan of the room and record sheet.
Where is this test used?
Periodic measurements of the lighting at workplaces for the purposes of occupational health and safety — offices, production halls, warehouses, laboratories, medical and educational establishments; Acceptance of new and modernised lighting installations — comparison with the design made in accordance with PN-EN 12464-1; Assessment of workplaces with combined lighting (general + local) and of workplaces with monitors; Checking of the ratio of the illuminances in adjoining rooms (≤ 5:1) and of the lighting of the circulation areas; Measurements on racks and shelves (a vertical plane) and on control desks.
What safety precautions apply?
Measurements after dusk with full lighting — in production halls agree access to the workplaces and the machines with the user; Do not touch the luminaires and the light sources; checking of the working order of the lamps only visually; Protect the photocell of the luxmeter against soiling and scratching — this changes its characteristics.
Which laboratory can perform this test?
The test is performed by laboratories accredited to ISO/IEC 17025. On LabCoda you can find them by the standard number PN-83/E-04040.