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You are here: Home Volume V February 2006 Product Review: Analyzing Reflectors: Part V

Product Review: Analyzing Reflectors: Part V

By Sanjay Joshi, Ph.D., Matthew Halloran Posted Feb 14, 2006 07:00 PM Pomacanthus Publications, Inc.
This article is a continuation of previous reflector articles and presents data and analysis of the remaining reflectors in Sanjay's inventory.

Since the last set of reflector tests in 2004, I have received five new reflectors for various metal halide lamps. This article presents test results on the fixtures/reflectors available for these lamps. The reflectors were tested using the same setup and methodology as used for the tests on other reflectors, described in [1]. The data is also presented in an identical manner with plots for light dispersion for each reflector at distances of 6", 9" and 12" from the center of the lamp. This article continues in a similar vein as the previous reflector articles and presents the data and analysis of the remaining reflectors in my inventory.

Table 1: Listing of the Reflectors Tested
Reflector Ballast Lamp
PFO Lighting New 400W/250W DE Reflector 400W PFO HQI Ballast HappyReefing 400W DE 10000K
PFO Lighting New 400W/250W DE Reflector 250W PFO HQI Ballast AB 250W DE 10000K
Icecap 400W/250W DE Reflector 250W PFO HQI Ballast AB 250W DE 10000K
Sunlight Supply - LumenMax 400W Magnetic Ballast (M59) USHIO 400W 10000K
Icecap 70/150W Pendant Icecap 150W Ballast Iwasaki PAR Lamp 6500K, Med base.

Reflector Data and Analysis

The data plots for each reflector at the distances 6", 9", and 12" are plotted as a surface graph, top view graph, and a % distribution graph to illustrate the intensity and spread at different points on the measuring grid. Table 2 below shows the list of figures associated with each reflector.

Table 2: List of Figures associated with each reflector
Reflector Figures
PFO Lighting new 400W/250W DE Reflector - 400W DE Lamp Figs. 1-3
PFO Lighting new 400W/250W DE Reflector - 250W DE Lamp Figs. 4-6
Icecap 400W/250W DE Reflector Figs. 7-9
Sunlight Supply - LumenMax Figs. 10-12
Icecap 70/150W Pendant Figs. 13-15

Figure #1: PFO Lighting new 400W/250W DE Reflector - 400W DE Lamp

fig1-pfode-400W-top.gif

Figure #2: PFO Lighting new 400W/250W DE Reflector - 400W DE Lamp

fig2-pfode-400W-par.gif

Figure #3: PFO Lighting new 400W/250W DE Reflector - 400W DE Lamp

fig3-pfode-400W-percent.gif

Figure #4: PFO Lighting new 400W/250W DE Reflector - 250W DE Lamp

fig4-pfode-250W-top.gif

Figure #5: PFO Lighting new 400W/250W DE Reflector - 250W DE Lamp

fig5-pfode-250W-par.gif

Figure #6: PFO Lighting new 400W/250W DE Reflector - 250W DE Lamp

fig6-pfode-250W-percent.gif

Figure #7: Icecap 400W/250W DE Reflector

fig7-icecap-250W-top.gif

Figure #8: Icecap 400W/250W DE Reflector

fig8-icecap-250W-par.gif

Figure #9: Icecap 400W/250W DE Reflector

fig9-icecap-250W-percent.gif

Figure #10: Sunlight Supply - LumenMax

fig10-lumenmax-400W-top.gif

Figure #11: Sunlight Supply - LumenMax

fig11-lumenmax-400W-par.gif

Figure #12: Sunlight Supply - LumenMax

fig12-lumenmax-400W-percent.gif

Figure #13: Icecap 70/150W Pendant

fig13-Icecap-pendant-top.gif

Figure #14: Icecap 70/150W Pendant

fig14-Icecap-pendant-par.gif

Figure #15: Icecap 70/150W Pendant

fig15-Icecap-pendant-percent.gif

One of the measures of a reflector performance could be its ability to direct light into the aquarium. A reflector's total incident light upon a surface of a given area is representative of the performance of a reflector. It is computed by adding up all the measurements taken at the discrete points within the region. It demonstrates how much light the reflector is able to focus downward when compared to other reflectors with similar operating conditions (same ballast and lamp). While it can be argued that adding all the PPFD values is technically not a valid measure as per the definition of PPFD (since PPFD is defined as microEinstiens/m2/sec), it can be used to provide a metric for reflector performance. Further summing over the data points on a given area can easily be used to compute the average, if so desired. Since the area under consideration is the same for all reflectors, we can just as well use the sum of the PPFD values distributed over this area (169 data points) instead of an average as a performance metric.

Table 3 presents this data for the reflectors in this article. Note that the initial PPFD values of the lamp/ballast combo used to test the reflector influences this data. For example, the PFO DE reflector used a 400W DE lamp on an HQI ballast with a PPFD value of 229 where as the Sunlight Supply Lumenmax used an Ushio 400W lamp on a magnetic ballast with a PPFD of 120.

Table 3: Total Incident PPFD on a given Surface area


Total Incident Light
Reflector: Distance: 3x3
Area
2x2
Area
1x1
Area
Maximum
PPFD:
PFO Lighting new 400W/250W DE Reflector - 400W DE Lamp 6" 61861 61756 55161 4226
9" 60400 58810 40033 2238
12" 55981 50333 28277 1468
PFO Lighting new 400W/250W DE Reflector - 2500W DE Lamp 6" 36452 36384 32389 2220
9" 34003 33052 22624 1180
12" 29966 26700 14748 750
Icecap 400W/250W DE Reflector 6" 42529 41921 33345 3176
9" 41750 37794 25596 1889
12" 39202 32480 18791 1168
Sunlight Supply - LumenMax 6" 46636 46542 28846 1682
9" 45596 44010 26180 1338
12" 45713 40933 21246 996
Icecap 70/150W Pendant 6" 22914 21987 18245 2539
9" 21486 19398 13871 1223
12" 20411 17386 10312 727

In addition to knowing how much light is incident on a given area, we could also look at how much loss of light occurs on a given area when moving the lamp and reflector higher. Table 4, presents the % of light lost on a specified area as one moves the lamp/reflector from 6" to 12" above the surface. A higher % loss would indicate that the reflector is creating a larger spread.

Table 4: Percent of PPFD lost from 6" to 12" from the lamp
Reflector 3x3'
Area
2x2'
Area
1x1'
Area
PFO Lighting new 400W/250W DE Reflector - 400W DE Lamp 9.5 18.5 48.7
PFO Lighting new 400W/250W DE Reflector - 250W DE Lamp 17.8 26.6 54.6
Icecap 400W/250W DE Reflector 7.8 22.5 43.6
Sunlight Supply - LumenMax 1.9 12.0 26.3
Icecap 70/150W Pendant 10.9 20.9 43.4

Conclusion

This article is the 5th (and possibly last) in this series and presents the data and a brief analysis some of the new reflectors I received in the past year.

Acknowledgements

We would like to thank several people whose help made this study possible. They were kind enough to provide us with lamps, reflectors and ballasts for testing: Patrick at PFO Lighting, Andy at Icecap, Dave at Sunlight Supply.

References

  1. Joshi, S. and Marks, Timothy. 2003. Analyzing Reflectors: Part I - Mogul Reflectors http://www.advancedaquarist.com/issues/mar2003/feature.htm
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