THE ENERGY BALANCE OF MODERN HIGH PRESSURE METAL HALIDE LAMPS

2002 ◽  
Vol 6 (2) ◽  
pp. 12
Author(s):  
M. Haverlag
Keyword(s):  
High Pressure ◽  
Energy Balance ◽  
Metal Halide ◽  
Metal Halide Lamps

Comparison Research of Street Lamps: Characteristic Parameters and Lighting Performance of Light-Emitting Diodes, High Pressure Sodium Lamps and Ceramic Discharge Metal Halide Lamps

2012 ◽  
Vol 229-231 ◽  
pp. 2610-2614
Author(s):  
Min Li ◽  
Qiu Yi Han ◽  
Wei Li ◽  
Shui Jun Shi ◽  
Hao Jun Zhang ◽  
...  
Keyword(s):  
High Pressure ◽  
Light Emitting Diodes ◽  
Metal Halide ◽  
Laboratory Measurements ◽  
Characteristic Parameters ◽  
Light Emitting ◽  
Road Lighting ◽  
Comparison Research ◽  
Color Rendering ◽  
Metal Halide Lamps

As a rapid developing solid state lighting, light-emitting diodes (LEDs) have great potential in application of road lighting, but their performance evaluation in a long term are still lacked. In situ and laboratory measurements were conducted for the purpose of comparing the characteristic parameters and lighting performance of three kinds of street lamps: LEDs, high pressure sodium (HPS) lamps and ceramic discharge metal halide (CDM) lamps. The results of laboratory measurements in 2000 hours show the three kinds of lamps have almost the same initial luminaire efficacy, which lead to the average road illuminance is proportion to the lamp power. The results of road illuminance distribution measurements in 3000 hours show LEDs have better color rendering index, longitudinal uniformity of illuminance, and maintenance of road illuminance than HPS and CDM lamps.

scholarly journals Supplemental Light Quality Affects Budbreak, Yield, and Vase Life of Cut Roses

HortScience ◽  
1993 ◽  
Vol 28 (6) ◽  
pp. 621-622 ◽  
Author(s):  
G.L. Roberts ◽  
M.J. Tsujita ◽  
B. Dansereau
Keyword(s):  
High Pressure ◽  
Total Energy ◽  
Quality Index ◽  
Light Quality ◽  
Metal Halide ◽  
Photon Flux ◽  
Vase Life ◽  
Photosynthetic Photon Flux ◽  
R:Fr Ratio ◽  
Metal Halide Lamps

Rosa ×hybrida `Samantha' plants were grown under high-pressure sodium (HPS) lamps, HPS lamps fitted with blue gel filters to reduce the red to far-red (R:FR) ratio, or metal halide lamps. R: FR ratios were 1:0.95, 1:2, and 1:0.26 for HPS; filtered HPS, and metal halide, respectively. Although the R: FR ratio for metal halide was 3.5 times higher than for HPS, the total energy from 630 to 750 nm was 2.8 times lower. At a nighttime supplemental photosynthetic photon flux of 70 to 75 μmol·m-2.s-1, plants under HPS and metal halide lamps produced 49 % and 64% more flowering shoots, respectively, than those under filtered HPS (averaged over two crop cycles). The quality index for flowers under HPS, metal halide, and filtered HPS was 25.0, 23.3, and 18.5, respectively. Vase life was 10 to 11 days, regardless of treatment.

Pedestrian visibility at night: The effect of solid state streetlights

2016 ◽  
Vol 48 (8) ◽  
pp. 976-991 ◽  
Author(s):  
R Saraiji ◽  
D Younis ◽  
MT Madi ◽  
RB Gibbons
Keyword(s):  
High Pressure ◽  
Solid State ◽  
Metal Halide ◽  
Night Time ◽  
Detection Distance ◽  
Different Types ◽  
The Mean ◽  
Metal Halide Lamps ◽  
Better Than

This study examines the effect of different types of lamps on pedestrian night time visibility. Detection distance was used as a measure of visibility. The detection distance was measured in the presence and in the absence of on-coming car headlamps in an unlit street. Subsequently, the street was lit using metal halide, high-pressure sodium or LED luminaires. A pedestrian who changed his clothing colour randomly was used as a target. The results showed that the detection distance on the unlit road was 52% shorter in the presence of on coming car headlamps than when the oncoming car headlamps were off. A person wearing black clothing was harder to see and their mean detection distance was 60% less than when the observer was not dazzled by the oncoming car headlights. When the street was lit, the detection distance was doubled. The mean detection distance using LED lamps was statistically similar to that obtained using metal halide lamps, both of which were better than the detection distance obtained under high pressure sodium lighting.

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