the impact of cie 140 on streetlighting in south africa
DESCRIPTION
THE IMPACT OF CIE 140 ON STREETLIGHTING IN SOUTH AFRICA. AUTHOR:- MURRAY CRONJE, BEKA (PTY) LTD. AMEU CONVENTION: DURBAN: 14-17 OCTOBER 2007. The CIE 140..., what for ?. To update and replace CIE 30.2 (1982), Calculation and measurements of illuminance and luminance in road lighting - PowerPoint PPT PresentationTRANSCRIPT
THE IMPACT OF CIE 140 ON STREETLIGHTING IN SOUTH AFRICA
AMEU CONVENTION: DURBAN: 14-17 OCTOBER 2007
AUTHOR:-
MURRAY CRONJE, BEKA (PTY) LTD
The CIE 140..., what for ?
To update and replace CIE 30.2 (1982),
Calculation and measurements of illuminance and
luminance in road lighting
It gives the methods which CIE 115 (1995) and
CIE 136 (2000) require for their recommendations
Was there a real need to update
CIE 30.2?
YES
CIE 30.2 came out just after the luminance concept was
accepted: there was very little experience with it.
And this is the CIE 140 major improvement: all the
things that experience has revealed during the past 20
years.
What are the most significant changes ?
Road surfaces characteristics are not dealt with any more
in this document
Luminous intensity data for luminaires are reviewed:
shorter angular intervals for I-tables
Interpolation methods for I-tables and r-tables are
reviewed and more completely developed
Calculation grids for both luminance and illuminance are
changed
New observer for TI
10° and 15° steps
10° and 15° steps
5° steps
5° steps2.5° steps
2.5° steps10 and 5° steps
Values of luminous intensities are required over the range of angular intervals
1° steps
Calculations will be more accurate, because we have more detailed information.
Interpolation of luminous intensity data
Linear Interpolation
C C Cm m+1
j+1
j
In the case of I, where we have measured values
in shorter angular intervals.
C C Cm m+2
j+1
j
j+2
Cm+1
Quadratic Interpolation
In the case of I, where we have measured
values in wider angular intervals.
S
D
D5m, N=10D=S/N
CIE 30.2
S
D
D/2
D3m, N=10D=S/N
CIE 140
For Luminance calculation
Before S = 50 m. Now S = 30 m.
D/2
For luminance calculations
x
x
x
x x xx x xx x x
Wl d =Wl/3
d /2
x
x
x
x x xx x xx x x
Before S = 50 m. Now S = 30 m.
d/2
For illuminance calculations
Wr/3
Wr standing for “Width of relevant area”
For Luminance calculation
W
W/4 Wt/2
WtWt/2
h=1,5m
60m
CIE 30.2 CIE 140
o : observer for Lave and Uo
x : observer for UL
ooo
oo
o
oo
The Lave
and U o re
tained are
the lowest
ones of th
e
three la
nes
TI Calculation
(%)28.0
aveL
EkTI
Before, k = 650
Now we do take the observer age into account
4
4.661641
Agek
TI calculations
2,75 (H-1,5m)
Before - only one observer position for TI calculations
Now - observer in the initial position and repeated with the observer moved forwards in increments which are the same in number and distance as are used for the longitudinal spacing D of luminance calculation points.
Example
- highway - 3 traffic lanes (Wt=3,5m), central reservation (5.5m)
- class A1 (SANS10098-1), Lav(2cd/m2), Uo(40%), Ul(70%), TI (15%)
- central pole position, H=13m, overhang 0m
- class R3, Qo=0,07
- BEKASTRADA SUPRA 400W HPS/T
l
v
l
l(m)
v(m)
2.5m
0.5m
57m
Results
S L Uo Ul TI E Uoe
CIE 30.2
60 2.28 40.2 79.4 12.2 27.6 0.42
CIE 140 57 2.82 40.1 82.4 11.8 34.1 0.46
2.59 40.0 77.7
2.33 42.0 79.9
Practical implications
• No more SABS 098 program for street lighting calculations
• Slightly shorter spacings• No more encrypted data• SABS to change their measurement methods• Municipalities to change their specifications to
exclude references to ;-• Data on 3.5 inch diskettes• Encrypted data• Designs to be done with SABS 098 program
Conclusion
• RSA now in line with the rest of the world
• Street lighting calculations now more accurate ensuring greater safety for motorists
• Users and suppliers now have a choice of which software to use
Thank you for your attention !