“Nipple Nonsense,” an article I wrote for the primary situation of Superior Aquarist was an try and systematically study a dialogue subject that had not too long ago made the rounds of on-line dialogue teams. It explored the notion that the place of the nipple, the small piece of glass on the inside envelope that is still when the envelope is sealed, makes a distinction within the efficiency of single ended metallic halide bulbs. The article produced fairly a bit of dialogue. Quite a few people got here ahead with logical explanations for why the nipple orientation of a metallic halide bulb does matter. A number of individuals took me to job for what they perceived to be flaws in my methodology. A handful of hobbyists got here ahead to say that they themselves had skilled bulbs altering colour simply by advantage of reorienting the nipple. Given the curiosity within the topic, the editor of Superior Aquarist determined that I ought to look somewhat extra intently at the phenomenon. The next report is predicated on further work accomplished after the publication of the primary report. Readers unfamiliar with the controversy ought to first learn Half 1 (Jan 2002 situation).
Many of the hobbyists reporting issues use single ended German 10,000 Okay bulbs within the 175 watt or 400 watt dimension. There are quite a few bulbs known as “German 10Okay” so one uncertainty is whether or not everybody reporting a distinction is utilizing the identical bulbs. I made a decision to look at the commonest German 10,000 Okay bulbs, the Aqualine Buschke and Ushio bulbs. (AB has distributed completely different 175 watt bulbs over time. I examined solely the AB bulb that’s bodily much like the Ushio model bulb.) For a few years hobbyists from across the nation have given me used bulbs to judge so I had a number of bulbs of various burn hours to check. These bulbs have been used on completely different ballasts by completely different hobbyists, and the hours burned are estimates supplied by the hobbyists, however testing a cross-section of used bulbs provided the very best probability of reproducing the experiences of these reporting an issue. To match used bulbs to a brand new bulb, new Ushio bulbs had been seasoned based on IES protocol and likewise evaluated.
Earlier than continuing it needs to be identified that this second spherical of testing differed from the testing for the primary article and was particularly designed to raised recreate the circumstances below which hobbyists reported a change in obvious colour of the mild generated by the bulbs. Within the first report the bulbs had been held regular and the sensors moved. For these further exams the sensor was stored under the bulb (the place the tank could be) and the bulb rotated. Two units of measurements had been taken, one set with the nipple pointing up away from the sensors and a second set with the nipple pointing down in direction of the sensors. The bulbs had been mounted in a naked horizontal free-standing socket with no reflector effectively away from any reflecting supplies. The socket could possibly be rotated in order that the bulbs could possibly be reoriented with a minimal of effort. Ambient mild degree within the room was checked between exams and at no time exceeded 1 uE/m^2/sec throughout testing. Every bulb was monitored whereas it warmed till it had stabilized as indicated by a gentle PAR studying, and solely then had been remaining measurements taken. After every bulb was examined it was allowed to chill to room temperature in the identical place. The bulb was then eliminated and changed with the subsequent bulb to be evaluated. All bulbs had been examined in a single orientation after which the sequence was repeated within the different orientation. The 175 watt bulbs had been examined with an IceCap digital ballast optimized for German bulbs. The 400 watt bulbs had been examined with a PFO HQI ballast. The sensor was rigidly mounted in a body positioned under the bulb and the space between sensor and bulb was set at 18 inches. Whereas my major curiosity was in colour temperature, depth or PAR was additionally measured. Spectral measurements had been additionally taken (knowledge not proven).
Desk one under exhibits depth and colour temperature for every 175 watt bulb in every orientation. The bulbs are designated by the hours reportedly burned. The development column refers to whether or not the bulb has a assist wire working alongside the envelope on the identical aspect because the nipple (designated with an “s”) or a assist wire on the other aspect of the envelope. These are designated with an “o”.
(see textual content)
There’s a measurable distinction between the depth in a single orientation and the depth within the different. Nevertheless, nipple orientation just isn’t a helpful predictor of which orientation generates extra mild. In some instances the nipple aspect produced extra mild and with others the aspect reverse the nipple produced extra mild. Because it turned out, the orientation of the assist wire was a greater predictor of which orientation produced extra mild at the sensor. The colour temperature of the bulbs different considerably from orientation to orientation, however the variations had been fairly small in all however one case. Not one of the bulbs took on a “yellow forged” as reported by hobbyists.
I’ve fewer samples of 400 watt German 10,000 Okay bulbs. Three had been evaluated, two used and one seasoned new bulb. Desk 2 exhibits the outcomes.
Building (see textual content)
Within the case of the 400 watt bulbs, all three produced the highest depth and colour temperature with the nipple pointed down in direction of the sensor. The distinction in depth between orientations was substantial, however the distinction in colour temperature would most likely be too small to visually detect.
In a number of makes an attempt, I used to be unable to recreate the colour shift phenomenon reported by hobbyists. There have been minor variations in colour temperature relying on nipple orientation, however the variations would most likely be too slight to be seen. In addition to the exams outlined above, I additionally reoriented heat bulbs to see if the orientation whereas cooling made a distinction. It didn’t. I additionally borrowed a bulb from one of many hobbyists reporting the issue and was unable to recreate the colour change. The hobbyist himself was unable to recreate the colour shift when he put the bulb again in service.
There are hobbyists which can be satisfied that orientation issues and demand that they’ve noticed the impact themselves. We even have hobbyists which can be equally satisfied that regardless of their bulbs’ orientation they produce the identical colour of mild. Given the variety of variables concerned in lighting together with the kind of bulb, the age of the bulb, the ballast, wiring, and the hostile setting of a reef tank, each teams are most likely appropriate. Underneath sure units of circumstances it may be attainable for some metallic halide bulbs to look yellow. Moreover, reorienting the bulb could change the colour of the mild. Nevertheless, with the info gathered up to now, it’s troublesome if not not possible to foretell below what circumstances and circumstances this would possibly happen not to mention decide whether or not reorienting the bulb will remedy the issue.
The difficulty of sunshine depth asymmetry is an equally thorny situation. Half one demonstrated that metallic halide bulbs are inclined to produce increased depth above the bulb than under it. These newest exams measuring depth solely under the bulb present that some bulbs produce significantly higher depth in a single orientation than the opposite. With some bulbs these asymmetries could be ameliorated by the design of the bulb and the orientation of it. The Iwasaki bulbs evaluated partially one confirmed much less asymmetry than the German bulbs evaluated right here. This means that it could be troublesome to predictably manipulate the sunshine depth discipline by reorienting the bulb until the particular bulb is evaluated. And there stays the query of whether or not we might need extra mild mirrored into the reflector or extra mild directed immediately into the tank even when we knew the particular asymmetry of a bulb. This can be a determination that every hobbyist must make. As I said within the conclusion of half one, given the quasi-point supply nature of metallic halide bulbs, it could be higher to orient bulbs with asymmetrical mild fields in order that extra mild is directed into the reflector. This may increasingly create a extra even mild discipline within the tank and scale back the opportunity of mild “scorching spots” immediately under the lamps.