Hi, I replaced my florescent with a mercury vapor bulb today. Self ballastered.

I positioned it above the basking platform, and measured the temperatures below it after it was on for like 30 mins. It was a little too hot. I noticed that the ceramic socket was quite hot too. So I switched it off, and positioned it higher up above the platform, and switched it back on again.

When it went on, I heard a slight rattling sound, almost like the sound when you switch on a florescent light in a garage, for about a second or so. The light switched on as normal, bright as ever, hot as before. Didn't think much about it then.

Now, I just read online that SBMVBs can burn out when you switch them off and then on again before they are 100% cooled off in temperature! In that website, it says that the bulb will completely burn out, no light, no heat, no UVB. But I can't help but wonder what was that fizzing/rattling sound?? It lasted like half to one second. Can it be that the UVB emitting mechanism has burned out but it still produce the same amount of light and heat???

I am not talking about a decay over months here. This is a brand new bulb. As long as the bulb switches on, it should still be emitting UVB, right?

How can you tell? I can't really get a UV meter now.

Hello,

To the best of my knowledge, if that MV is producing light, it is producing UV. (Of course this would not be true if the light were old and was decayed.)

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I have heard a similiar noise with my EBs and in the past with my SBs. I know the EBs are still giving off UVB since I have a meter now. I have also seen a very slight flickering in a few of mine but again I have tested them and found they are fine. Both EBs and SBs do take about 15 minutes to come on if you try to turn it on right after turning it off--I guess because of the heat. I do not know of a way to know for sure though without having a meter though.

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Jan. 25, 1963 - Sept. 10, 2006 (R.I.P)

Which MVB are you using? SOME of the brands have a safety feature on them to where they wont turn on untill completely cooled. I know mine are the way, and beleive it or not some times during the day, if it gets too hot, it shuts itselft off and comes on about 10 minutes later...

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Jayr & Mandy Robinson
J&M Herp Shack
"Are you watching closely?"

empoyner, have you heard that same flickering/rattling sound with your SBs and tested any to see if they were affected at all? I really can't afford a meter now but I just want to know if that sound means it is DEFINITELY not emiting UVB or it is a normal sound that occurs now and then and that should not be worried about.

jmherp, I am using "Rep Pro" brand SB MVB.

I didn't get my meter until after switching to the EBs. But I would hazard to guess that the same would be true with SBs.

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Jan. 25, 1963 - Sept. 10, 2006 (R.I.P)

Replover, you did indeed break the cardinal rule of SB Merc Vapor lamps.

SB MV lamps have a very fragile filament. They should never be moved around while hot, that is when the filament is the most fragile. Also, they need 15 minutes to reset.

Based on what I see with the RepPro lamps, they should be fine. They are strong, though unstable, UVB producers. If it lit up again, it is emitting UVB. We are currently testing these lamps at ReptileUV.

These lamps do burn extremely hot! Please make sure they are in a ceramic socket fixture, firmly mounted to an unmoveable surface and out of complete reach of the iguana, a wire cage around the face of the lamp fixutre is best.

Glad to hear you have them. I would have loved to ship you a Mega-Ray lamp, but shipping to China is extremely expensive, so this is a good option.

As with the rest of your set-up, quit playing with it! LOL You need to give things time. Those lamps will burn bright and hot until the burn-in phase is over, then things will change.

As long as the iguana can move away from the light and heat, there is no danger in it.

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Regards,
Dominick
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"Do you watch too much television? Did you do so as a toddler? Evidence tonight that it could be the cause of learning disorders, like attention deficit and hyperact-Ooooh, a kitty!" - Keith Olbermann

Donimik, Yes I know I broke the cardinal rule, hence my posts.

I can look up into the lamp from where I stand inside the enclosure and see the wires. There are like some thickish wires sticking out from the base of the lamp, connected by some springs. I can see it clearly and the springs are all intact. There is also a "Glass case" inside that has two wires on either end and a "Cup" on their middle. There is no wire connecting these.

When you say "it should be emiiting UVB if it is emmitting light", you only refer to that as in SUDDEN damage, right?
So, after say, 6 months, even if it is still emitting light, it may have "decayed" to the point of no UVB, and need to be replaced? Or can I use it as long as it is emitting light? In other words:
1) SUDDEN damage when bulb is new and hasn't decayed over time - if it has light, it is still OK UVB wise.
2) GRADUAL DEGRADATION over time, it can still be emitting light but UVB amount has decreased to nothing/nill?

Otherwise, I don't see how you can make sure they haven't been moved or shaken around because they are shipped from overseas by the bulk and I KNOW how terribly the postal service handles packages. I run a mail order business, and when packages get returned, they are completely CRUSHED.

I would be VERY interested in seeing the results of your tests at Reptile UV of these rep pro bulbs. Please let me know as soon as you have any results.
When it comes time to replace my bulb in a few months (6? 8 months?), I would very much also be interested in trying a MEGA RAY. I wouldn't mind paying extra shipping unless it is outragous but that depends on the postal service. Please do let me know then.

I heard that there are these "UV test cards" that are like little plastic cards (business card sized) that test the relative strength of UVA and UVB. I know they are not nearly as accurate as the meters, but I would presume they are cheap, and they can at least give an idea of whether the bulb is working AT ALL or completely broken. I saw them but have no idea where to get them. They are meant for beauty conscious women who test the sunlight for UV before they go outside to estimate what SPF sunscreen they should wear. LOL!

All in all, should I feel reasonably safe that the light is still working now? It still has light as before. Over the past day of burning, it has graudually dimmed somewhat (at first it was hurting my eyes so bad!). Not much, but it is noticeably a little dimmer than the first switch on. The color of the light is the same. White colored light. When shone on the platform, the circle is a kaladoscope of different colors, red, yellow, blue, green and white. Is that gradual decrease in light normal? What could that rattling sound have been, in your experience with MVBs? I haven't heard that in the subsequent times the light was switched on. I just want to make sure the IG is getting proper UV.

I may add, I took a quick look at the bulb while on, and I notice that the light is coming from the little glass case inside it. It was shining like a ball of light and thats where pretty much all the light came from. It looks so fascinating!

Anthony-

I see that you ask very similar questions on other forums.

To answer your questions:

This lamp will decay, as all MV lamps do. Some of these lamps decay quickly, some slowly over time (the inconsistency factor once again). We all face the very same issue. The only REAL way to be sure of UVB output is with a meter. I would be intersted in looking at these UVB cards. Sounds like an interesting concept. The lamp will give you 4-6 good months of UVB, after that time, it will be questionable and can only be confirmed by measurement with a meter. That's why I suggested you get a couple of these lamps to start with. Yes, over time the lamp will decay and even though it is emitting light, it's UVB might be weak. Right now, I don't think that the sizzling caused any damage.

Never look into the light of a working mercury vapor lamp. It's the equivelant of looking into the sun without sunglasses to block the UVB.

The elongated nature of these clear-faced lamps require that they be housed in a ceramic socketed, deep "reflector" hood. The UVB is scattered out of the entire lamp, so the relfector hood focuses the light and UVB down toward the target area. Very important!

They are not as fragile in a cooled state, that's why we can ship MV lamps in the mail and they still work. They are only fragile when the filament is still hot. Hence, the 'don;t move them when hot' rule.

Interesting thought: You don't order anything through the mail, yet you own a mail-order business?? Seems like diabolically opposed positions. LOL The saying goes (for store purchased things), "If you bought it, a truck brought it". Trucking, in my extensive experience, is just as hard on product as shipping through the mail. So, the same rules apply. LOL

I think your lamp is just fine. If you are overly concerned why not return it to the store for replacement. Tell them the thing "flickers" and you don't trust it. They should replace it without issue, if they stand behind their product.

Write to me privately at dom@reptileuv.com with a shipping address and I will see how much it costs to ship to China. We can go from there.

Keep up the good work!

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Regards,
Dominick
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"Do you watch too much television? Did you do so as a toddler? Evidence tonight that it could be the cause of learning disorders, like attention deficit and hyperact-Ooooh, a kitty!" - Keith Olbermann