General Question

delirium's avatar

Is there a quick and painless way to find the wattage on a very very hot bulb that I can't turn off?

Asked by delirium (13691points) May 2nd, 2008

My Uromastyx lizard’s cage is running a bit hot with the change in temp. He’s extremely susceptible to cold, though, so I don’t want to shut off his primary heating lamp for the time it would take for it to cool down enough for me to take it out and examine the bulb for any writing on it. I need to go out and get a slightly lower wattage bulb for the summer, but I don’t know what the wattage of this current one is. These bulbs are REALLY expensive, so I can’t guess and check. According to my laser tempgun the bulb itself is over 400 degrees F on its surface. Any way that I can figure out the wattage without having to sneak it out silently in the night, go find a light, and examine it?

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25 Answers

Breefield's avatar

So, my solution to your perplexing predicament is this.

The problem we have is that you don’t know what temperature littlefoot likes most, but you need to be able to remove the halogen bulb long enough for it to cool down so you can find it’s wattage, and buy a new one.

What you’re going to do it build a bonfire, remove the lid to littlefoots cage and let the bulb cool down. Now set the cage next to the bonfire longways. Then littlefoot can decide how close it too close to stay warm.

richardhenry's avatar

If you use oven gloves, it will resist the heat of the bulb. Just take it out, carefully check, and then replace.

Breefield's avatar

Maybe use several layers of over gloves.

delirium's avatar

Do I run any risk of shorting out the light if I do it without unplugging it?

richardhenry's avatar

Yes unfortunately, the fuse or trip switch might be triggered. You should disconnect the lamp while you remove the bulb.

@Breefield: Or use oven gloves? They’re designed to resist temperatures much hotter than a halogen/heat bulb, and won’t get melted on contact. :)

delirium's avatar

UPDATE: Uh…. the oven mit started to burn. Its sitting in the sink now.

Breefield's avatar

Hah! told ya so. Use multiple layers, then if the first layer burns off you’ll have a reserve :p

delirium's avatar

Bree, sweety, there will be no going to the vet because of smoke inhalation. Reptile vets are wickedly expensive.

Also, in response to your first solution. There is no setting of this cage anywhere. Its over four feet and is made of solid wood that has insulation chambers, places for extensions, wiring up the wazoo… etc.

soundedfury's avatar

If you have a desk lamp, you can use that to slow down the loss of heat when you turn off the heat lamp. It won’t maintain the temp, but it will slow down the loss.

What type of heat lamp is it?

delirium's avatar

Some kind of halogen bulb in one of these which melted slightly on one occasion…

delirium's avatar

If the decline if temp is going to be that long, it’ll fuck with his little head. He’s just coming out of brumation and I don’t want to mess that up. :(

I’m sorry that this is so complicated. If it were simple I would have done it myself without asking…

soundedfury's avatar

Sorry, *del, there isn’t a conversion from surface temp to wattage or this would be easier. You’ll just have to wait until night and creep like a ninja.

delirium's avatar

Okay, sincerely thanks for trying. :)
(Littlefoot thanks you too)

gooch's avatar

my firefighter gloves are top covered with leather. Use your ovenmit but cover it with leather or maybe a couple layers of aluminium foil. That will protect the mit and the mit will protect you.

nikipedia's avatar

Well now soundedfury has got me thinking. Are you sure about that?

1 watt is 1 joule per second.

1 joule is the amount of energy it takes to heat 1 gram of air by 1 degree celsius.

Shouldn’t there be a conversion factor in there? If we knew the exact temperature of the air and the exact amount of air we were taking the temperature of and the exact length of time it took the air to heat up? This is starting to feel like an MCAT problem…

soundedfury's avatar

Sure, if we knew everything about the bulb and environment except the wattage. What I meant was that there isn’t a real-world applicable conversion.

mac316's avatar

delerium, this may sound a little elementary but the easiest way to get the wattage is with a wattmeter. While you probably don’t have one, ask around with your techie buds. You can come up with either that or an ammeter. Either can get the wattage you need. If it’s the wattmeter, it reads directly, if it’s the ammeter it will give you a figure like 2.5 amps this miltiplied by 120 ( the voltage) will give you the watts.

The real problem will be in finding a slightly smaller lamp, as these lamps are made in fairly wide steps. For example, 150 to 300 watts.

delirium's avatar

I can, luckily, change the lamp in surprisingly gradual steps. And if it ends up being too cold I have ceramic heaters for him in there too.

Thank you so much. That wattmeter is exactly what I was looking for. I really really appreciate it. I… hadn’t ever heard of one.

Foolaholic's avatar

Is this a lamp that’s built into the top of the cage? Because if not, could you not simply increase the distance of the lamp from the cage in accordance with your needs?

richardhenry's avatar

Oh god, sorry about the gloves.

I looked up the temperature of a halogen lamp, but I think the article was wrong… most oven gloves are certified to 350 degrees celsius, which is plenty above as hot as things in the oven can get, and this article claimed a halogen lamp can reach 250 degrees max, so two plus two means the gloves should have been okay.

In reality, 250 degrees is the temperature at which convection begins to take place in the bulb, and the bulb wall can actually hit temperatures ranging from 400 to 1000 degrees celsius.

Yeah, you really shouldn’t try touching that thing while it’s on. Sorry for the misadvice. :(

delirium's avatar

Its okay. :) it was worth it trying to explain to my mom why the oven mitts were charred.

lrk's avatar

Perhaps a silly question, but why don’t you know what the wattage (or the rating in lumens, for that matter) is of the lamp? Did someone else install it for you? (I.e., can you ask whoever created the setup? Maybe the pet store gave you a certain recommendation that you used?)

delirium's avatar

Sorry irk, I appreciate the answer, but this was back in may. ;) Might want to check the date once in a while.

lrk's avatar

Man. I blow. So did you finally solve it? :D

RocketGuy's avatar

Perhaps you can prepare a hot water bag for the little guy, then unplug the heater. When the heater cools, you can examine the bulb for wattage numbers.

You can borrow a friend’s ohm-meter to see how many ohms between the prongs of the plug. W=V^2/R. V=120volts, R is measured, W = wattage. If you are lucky, your friend would have a Kill-a-watt gadget he can lend you to directly see how much power is being used.

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