CBT-140 to replace mercury vapor arc light?

CNCUnlimited · Aug 22, 2015

Hello all,

I have a machine that currently uses a mercury vapor arc lightbulb (sah-250b). It appears to be rated at 10,000 lumens. These bulbs are obsolete and expensive ($500-$700) to replace. I would like to replace it with a suitable LED, but I am not well versed in the finer points of LED specifications and would like some feedback from people who are.

The machine is an optical comparator used for precision measurement. If you google "optical comparator" and select images, you will see plenty of examples of what it is and should give you an idea of what it does.

Some questions I have off the bat are, I think I need a single emitter light source due to the light being lensed into a parallel beam and then projected onto the screen. I believe multiple/large emitters would have issues working with the existing optics. Thoughts?

Also, due to the high magnification and numerous optics involved, it takes a really bright light to get a visable image on the screen. I'm not sure you could have too much light, but a dimmer is probably necessary as the magnification is variable.

So, having said that, doing some research, it seems the CBT-140 from Luminous seems to be a possible candidate. These suckers are expensive at nearly $100 a piece, otherwise I would just buy it and try it.

So, what do you ll think? Am I on the right track? If so, I could use some help selecting color/flavor as I have NFI what all the nomenclature means. Also, I need some ideas on how to power it.

Thanks in advance for any insight.

Brian

SemiMan · Aug 22, 2015

CNCUnlimited said:
Hello all,

I have a machine that currently uses a mercury vapor arc lightbulb (sah-250b). It appears to be rated at 10,000 lumens. These bulbs are obsolete and expensive ($500-$700) to replace. I would like to replace it with a suitable LED, but I am not well versed in the finer points of LED specifications and would like some feedback from people who are.

The machine is an optical comparator used for precision measurement. If you google "optical comparator" and select images, you will see plenty of examples of what it is and should give you an idea of what it does.

Some questions I have off the bat are, I think I need a single emitter light source due to the light being lensed into a parallel beam and then projected onto the screen. I believe multiple/large emitters would have issues working with the existing optics. Thoughts?

Also, due to the high magnification and numerous optics involved, it takes a really bright light to get a visable image on the screen. I'm not sure you could have too much light, but a dimmer is probably necessary as the magnification is variable.

So, having said that, doing some research, it seems the CBT-140 from Luminous seems to be a possible candidate. These suckers are expensive at nearly $100 a piece, otherwise I would just buy it and try it.

So, what do you ll think? Am I on the right track? If so, I could use some help selecting color/flavor as I have NFI what all the nomenclature means. Also, I need some ideas on how to power it.

Thanks in advance for any insight.

Brian

Realistically, this will be very difficult, bordering on impossible to be done with an LED. You are correct, you need an exceptionally bright point source, and off the shelf LEDs just are not there. Add in, you have a complex optical arrangement (reflector, lenses, etc.) all built around a specific spherical radiating source.

That said, you may be able to convert to a more modern arc light, i.e. UHP, which is still Mercury arc, but perhaps is more readily available, cheaper, and lasts longer. It looks like there may be adapters for other bulbs to replace yours, but I did not dig too far.

CNCUnlimited · Aug 22, 2015

SemiMan said:
Realistically, this will be very difficult, bordering on impossible to be done with an LED. You are correct, you need an exceptionally bright point source, and off the shelf LEDs just are not there. Add in, you have a complex optical arrangement (reflector, lenses, etc.) all built around a specific spherical radiating source.

The CBT-140 seems like it would do the job, no?
http://www.luminus.com/products/CBT-140.html

SemiMan said:
That said, you may be able to convert to a more modern arc light, i.e. UHP, which is still Mercury arc, but perhaps is more readily available, cheaper, and lasts longer. It looks like there may be adapters for other bulbs to replace yours, but I did not dig too far.

I have briefly read about halogen bulb conversions for these. I would consider it, but I like to be cutting edge, so, a possible LED upfit was my first choice. If that proves problematic. I will look into the halogen conversion.

Brian

NoNotAgain · Aug 22, 2015

Yes, it's a lot of money, but whatever you get as a replacement is going to require fabricating some type of holder and a power supply.

I've no idea how old your shadow graph is, but I'd look for companies that sell and service microscopes and let them have a go at it.

After looking at some of the retail pricing for this lamp, I'd bite the bullet and do a direct replacement.

SemiMan · Aug 22, 2015

Lamp is discontinued ... But there seems to be adapters out there for other bulbs.

NoNotAgain · Aug 22, 2015

There's two on a popular auction site. Rather pricey, but available. http://www.ebay.com/itm/Bulb-for-PH...0WATTS-/141486205928?var=&hash=item20f13c2be8

Then there's this as a complete replacement. http://www.ebay.com/itm/like/180884091631?ul_noapp=true&chn=ps&lpid=82

We scrapped a microscope because the xeon light/power supply blew up. The Olympus rep wanted more for the custom repair that getting a newer Nikon.

Hooked on Fenix · Aug 23, 2015

I would think l.e.p. (light emitting plasma) would be a better fit for an application needing 10,000 lumens and a single focused light source.

SemiMan · Aug 23, 2015

Hooked on Fenix said:
I would think l.e.p. (light emitting plasma) would be a better fit for an application needing 10,000 lumens and a single focused light source.

As long as you are up to the full custom optical design then maybe. They are not a spherical source.

CBT-140 to replace mercury vapor arc light?

CNCUnlimited

Newly Enlightened

SemiMan

Banned

CNCUnlimited

Newly Enlightened

NoNotAgain

Flashlight Enthusiast

SemiMan

Banned

NoNotAgain

Flashlight Enthusiast

Hooked on Fenix

Flashlight Enthusiast

SemiMan

Banned

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