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The mobile vehicle shall not produce light or electronic noise that interferes with the instrument reading unless the instrument reading is corrected adequately and this correction considered in the uncertainty evaluation.

If the luminance detector is located inside the vehicle all the effects of the windscreen and of light inside the vehicle have in the luminance reading shall be evaluated and the measured values shall be corrected. This correction shall be considered in the uncertainty evaluation.

The mobile observer concept can be adopted. In this case the nominal angle of view of the meter shall be at 89° to the normal to the road surface and the measured grid points shall be in the transversal lines at the distance corresponding to the required angle of view with a tolerance of ± 2x D, where D is the spacing between points in the longitudinal direction of the grid specified in EN 13201-3.

For measurements at the final testing phase, the maximum distance covered during the exposure time shall not be greater than 0,5 m and the accuracy in the definition of the nominal coordinates of the measurement points shall be better than D, where D is the spacing between points in the longitudinal direction of the grid specified in EN 13201-3.

For measurements during the lifetime of the installation, the maximum distance along which the sensors perform the measurements (during the acquisition time) shall not be greater than 2,0 m.

Any of four different type of illuminance shall be measured, depending on the lighting class or classes of the road lighting installation. These are:

• horizontal illuminance,

• hemispherical illuminance,

• semicylindrical illuminance,

• vertical illuminance.

Some points of the grid can be located in the shade of objects (i.e. trees). In such cases, it is recommended not to consider these points in the determination of the average and/or minimum illuminance and the uniformity values and to recorder these points in the test report. Alternatively, the appropriate particular parameters should be evaluated. The algorisms of the informative Annex В can be used.

For horizontal illuminance measurements the plane of the light sensitive surface of the photometer head shall be horizontal or parallel to the conventional road surface plane.

The nominal value of the height of the plane of the light sensitive surface of the photometer head (measurement height) shall be specified in the test report (see 7.3.7 and 7.3.8).

Theoretically the light sensitive surface of the photometer head should be positioned at ground level but generally this is not possible because of the detector thickness and any support e.g. gimbals.

NOTE 1 If the measurement height increases then discrepancies between the measured values and the real or

calculated illuminance on the road surface increase too.

The influence of the measurement height shall be evaluated in the measurement uncertainty. If possible a correction factor for the measurement height should be determined. In this case the measurement uncertainty shall consider the corrected illuminance value and the influence of the correction factor uncertainty.

NOTE 2 A factor to correct for the measurement height is obtained by evaluating for every point of the used grid the ratio between the calculated illuminance on the road surface and the calculated illuminance on the plane at the nominal measurement height and parallel to the road surface.

Hemispherical illuminance at a point can be measured by means of an illuminance meter for measuring planar illuminance by adopting the following procedure. The horizontal illuminance Eh.m from all the luminaires is measured at the point. The component Ei,_m is measured from the /-th luminaire in turn by directing the surface of the photometer head so that it receives light at right-angles to its surface from this luminaire, and all other light is excluded. The measured hemispherical illuminance Ehs.m is given by: where

^hs,m ^h,m

ⁿlu

A ^r'/,m /=1

(1)

Eh.m is the measured horizontal illuminance from all the luminaires of the road lighting installation;

Ei,_m is the measured perpendicular illuminance from the /-th luminaire;

ni_u is the number of luminaire of the road lighting installation.

The other conditions for hemispherical illuminance are the same as the condition for horizontal illuminance.

The centre of the light sensitive surface of the photometer head shall be positioned nominally at 1,5 m above ground level. The light sensitive surface of the photometer head shall be vertical and have the correct orientation, typically facing longitudinally. Guidance is given in EN 13201-3.

The centre of the light sensitive surface of the photometer head shall be positioned nominally at 1,5 m above ground level considering the grid points defined in EN 13201-3. The light sensitive surface of the photometer head shall be vertical and have the correct orientation, typically at right angles to the main directions of pedestrian movement. Guidance is given in EN 13201-3.

When illuminance is measured, to minimize interference from measurement systems or operators it is recommended that either an illuminance meter with photometer head attached to the meter by means of a cable or an illuminance meter with a remote hold cable shall be used. Cables shall be sufficiently long for observers to position themselves so that they do not obscure any of the light that would otherwise reach the photometer head.

The use of gimbals eases the task of maintaining the photometer head at the correct inclination, with respect to the conventional road surface plane.

For horizontal illuminance the measurement height shall be within 200 mm of ground level. If the road lighting system has luminaire at heights lower than 2 m the photometer head shall be within 50 mm of ground level or illuminance values shall be calculated also at the rated measuring height.

In principle the mobile vehicle shall not shield lights that would otherwise reach the photometer head, unless these conditions are considered in the measurement procedures (as in split detector systems).

If the split detector method is adopted, the shield effect of the vehicle is considered in the measurement procedures. An estimation of the accuracy of the algorithm for obtaining the point illuminance from the front and read detector reading shall be considered in the uncertainty evaluation.

NOTE Guidance on design, use and metrological characterization of split detector systems is given in CIE 194:2011.

Any effects on the detector readings generated by the vehicle, such as shadows cast by the vehicle, light reflected from the vehicle, inter-reflection between the vehicle, the detector and its case, if present, shall be corrected and shall be considered in the uncertainty evaluation.

The mobile vehicle shall not produce light or electronic noise that interferes with the instrument reading unless the instrument reading is corrected adequately and this correction considered in the uncertainty evaluation.

If safety reasons justify it, the height of the photometric head shall be within 300 mm of ground level. If the road lighting system has luminaire at heights lower than 2 m illuminance values shall be calculated also at the rated measuring height.

For measurements at the final testing phase, the maximum distance along which the sensors perform the measurements (during the acquisition time) shall be no greater than 0,1 m.

For measurements during the lifetime of the installation, the maximum distance along which the sensors perform the measurements (during the acquisition time) shall not be greater than 1,0 m.

The Edge Illuminance Ratio shall be measured following the requirements given for the measurement of horizontal illuminance and grids specified in EN 13201-3:2015, 8.6.

When the measured illuminance values in the grid points are known, the edge illuminance ratio is calculated using the following formulas derived from formulas specified in EN 13201-3:2015, 8.6, Formulae (42), (43) and (44):

n _ E h,stripl,m

^wEI12,m“= —

6 h,strip2,m

n _ £ h,strip4,m

^KEI43,m - = I⁶ J

6 h,strip3,m

^EI,m ^=min(^EI12,m,-^/?EI43,m) (⁴)

In some circumstances illuminance measurements in the zones outside the carriageway is difficult or impossible to obtain. In these situations the edge illuminance ratio cannot be measured but the ratios between the measured average horizontal illuminance and the calculated average horizontal illuminance of the same carriageway strips shall be given in the test report.

NOTE For example these zones are not accessible, not flat or with obstacles or shielding objects.

If required the threshold increment can be measured with the following procedure.

If niu is the number of luminaires involved in the calculation of the threshold increment (see EN 13201-3:2015, 8.5), the threshold increment at the measurement instant is obtained considering the measured average road luminance, the measured illuminance produced by the /-th (/ = 1, ..., n,_u) luminaire on a plane normal to the line of sight and at the height of the observer’s eye, the angle between the line of sight and the centre of the /-th luminaire and using the algorithm of EN 13201-3:2015, 8.5, Formulae (35), (36), (37) and (38) here repeated with the obvious changes of symbols:

/TI,m=654g- (5)

fm

ⁿlu

^v,m ⁼^2^v/,m (6)

/=1

and

L_vl,_m=9,86

^Ay

<66,4 J

0l,_m

if 1,О°<0_/дп<6О°

(7)

o

(8)

r

6>,³ 6»,² 62,5 ,

^ly/,m ^u/,m V /

where the same constraints of EN 13201-3:2015, 8.5 shall be considered and:

Lv.m is the equivalent measured veiling luminance in candelas per square metre;

Lvi.m is the equivalent measured veiling luminance of the /-th luminaire, in candelas per square metre;

/ is the index of the pending luminaire in the summation;

ni_u is the number of luminaires of the road lighting installation that have an angle 0i,_ra in the range specified in Formulae (7) or (8);

E,_m is the measured illuminance produced by the /-th luminaire on a plane normal to the line of sight and at the height of the observer’s eye, in lux;

0i,_m is the measured angle between the line of sight and the centre of the /-th luminaire, in degrees;

Ay is the age of the observer, in years.

During measurement at the final testing phase the observer positions shall be the same as those adopted for calculation. Only the position that gives the highest values of the threshold increment (worse situation) in calculation can be verified.

If an 1LMD is used:

1. the illuminance produced by the Д'-th luminaire can be obtained considering the measured luminance of the luminaire and the angle 0k,_m;

2. the 9k,_m angle can be obtained from a perspective analysis on the acquired image if the device allows it, or by the reference to the calculation process of EN 13201-3:2015.

The uncertainty of these parameters is strongly correlated to the optical properties of the ILMD (i.e. focal length of the lens, dimension of pixels of the detector array), of its optical and geometrical calibration and of the road lighting installation dimensions and layout. The focal length of the lens and the dimension of pixel of the detector array of the ILMD shall be given in the test report.

8. Measurement of non-photometric parameters

   1. General

The selection of non-photometric measurements should be related to the purpose of the measurements (see 5.1).

It is strongly recommended where measurements are performed for comparison with requirement, detailed non-photometric measurements are required.

Where the measurements are required for monitoring the state of an installation then it is possible that less detailed non-photometric measurements will suffice

When required, during the measurement the supply voltage shall be measured continuously or at least at the beginning of the measurement at a significant point in the electric installation, and observed.

NOTE 1 A recording voltmeter is preferable for this purpose.

NOTE 2 If the emitted luminous flux of the luminaires in the road lighting installation is considered stable when subject to variations of the supply voltage then the continuous measurement of supply voltage is not necessary.

When required, the temperature and humidity shall be measured at a height of 1 m above ground level and recorded at least at the beginning of the measurements and eventually regularly along the measurement period.

If required, measurements shall be made of the geometry of the installation (see informative Annex E).

These may include measurements in plan of the installation, the height of the columns, and the length of the outreach. In addition tilt in application of the luminaires, orientation of the luminaires, and rotation of the luminaires shall be assessed if this data is relevant for meeting the aims of the measurement.

The measurement of non-photometric parameters that are relevant for the measurement aims shall be carried out with calibrated instruments.

The decision to use non-calibrated instruments for specific non-photometric parameters shall be reported in the test report. For these parameters measurement uncertainty shall not be evaluated.

NOTE Requirements for quality assurance of instruments may be requested as part of a tender or specification.

8. Test report

The test report should contain at least:

1. the objectives of the measurement;

2. all information gathered during the measurement if relevant for the aim of the measurement;

3. details of the instruments used, their number for an unambiguous identification and their calibration conditions (date, validity and metrological traceability);

4. details about the weather, environmental and electrical power supply conditions;

5. a reference or a short description of the procedures adopted for measurement and data elaboration, including the measurement uncertainty evaluation;

6. the measurement results with their measurement uncertainty;

7. the reason, justification and consequences of the selection of zones of the installation if it is not measured for its total length;

8. action taken to prevent or account for direct or reflected light from the surrounds;

9. all the other information mentioned in the previous clauses.

For dynamic system the average vehicle speed during the measurements shall be specified and the measurement uncertainty evaluation shall clearly indicate all the aspect correlated to movements and the correction factors eventually introduced.

The person responsible for the measurements shall sign the test report.

An example of test report is proposed in the informative Annex H

.Annex A
(informative)

Evaluation of tolerances in road lighting installation design

A.l Tolerance analysis

A lighting project aims to guarantee a road lighting installation working in accordance with the required performance conditions (photometric quality parameters), considering any reasonable variation of key parameters that influence its performance.

The tolerance analysis is a mathematical tool for evaluating the influence in the expected performance values of the given road lighting installation of:

1. the tolerance in manufacturing of luminaires and light sources with reference to rated values (these tolerances are specified in product standard or are specified by manufactured);

2. the tolerance of the layout of road lighting installation and of the installation of the light source with reference to rated values specified by the design;

3. the measurement uncertainty of the road surface photometric characteristics (if luminance is considered).

NOTE The concept of manufacturing tolerance entails that the measurement uncertainty of parameters that characterized luminaires and light sources is lower than the manufacturing tolerance itself, because the measurement uncertainty is considered in specifying the tolerance interval of these products (see ISO/IEC Guide 98-4).

Tolerance analysis can be used during the design phase:

4. to reduce the installed energy used to the minimum level while meeting the required lighting performance parameters;

5. to reduce the installed luminous flux to the minimum level that guarantees the required level of performance, independently from the variability of the key parameters;

6. to understand the importance of a given key parameter in the depreciation of a photometric quality parameter compared to the design value;

7. to highlight the key parameters that should be controlled to minimize the risk of a road lighting installation not satisfying the design requirements;

8. to clearly specify road lighting installation constraints and requirements.

Using tolerance analysis the lighting designer can verify and/or state the probability that the installation will satisfy the required performance characteristics.

Tolerance analysis can also be used to evaluate reasons for discrepancies between measurement results and design expectations.

A.2 Parameters to be considered in the tolerance analysis

Tolerance analysis evaluates the sensitivity of nominal values of photometric quality parameters of a particular road lighting installation to the variation of the selected key parameters.

The main influencing parameters are indicated in Table A.l Other parameters should be considered if known or if important for the layout of the road lighting installation or the type of luminaire adopted.

Table A.l — Main influencing parameters for tolerance analysis