am i reading it right?

[sher]

picked up Marine Fish and Reef 2002. i was reading the lighting part of the mag. came across the AL 150w HQI test. it gives a par at 246. now my ? is: is that 150w HQI setup going to be better then a 250w HQI setup?? with a par like that, one would not have to buy 400watters. is that correct or is there still a difference??

TIA,

souk

[Ninong]

The figures are not comparable because in all of Sanjay's other tests the lamps are tested 18" from the receptor without a reflector of any kind and without a UV-absorbing shield.

In testing the AB-10000 150w HQI DE lamp he decided to place it in a PFO light fixture with a reflector and UV-absorbing glass shield. So two factors are different here: (1) The reflector, which would increase the concentration of the light and increase the PAR measurement, and (2) The UV-absorbing glass shield which would decrease the PAR by approximately 10-15%.

The 150w HQI DE lamps are not stronger than the 250w HQI DE lamps but they are stronger than some 250w mogul base lamps, such as the Blueline 10,000K 250w mogul base lamp and the ALS Sunburst 12,000K mogul base lamp.

It would be great if Sanjay would start testing all of his lamps in some sort of a fixture but as long as all of the tests are from the same distance above the receptor (18") and all without a reflector, then the numbers are comparable. The only thing the reflector would do would be to increase all of the numbers... and if he were to test with the lamps only 9" away from the receptor, all of the numbers would quadruple.

So the bottom line is that this test of the 150w HQI DE lamp is the only one so far that cannot be compared to all of the others. I believe a lot of people pointed out that the earlier test of the Ushio 250w 10,000K HQI DE lamp was performed without a UV-absorbing glass shield even though in that same article Sanjay cautioned that it should never be operated without one.

Ninong

[sher]

thx Ninong,

so 250w HQI are still better..

souk