When I say "modern" I am talking about two topics: compact metal halide lamps, and LED halogen retrofits. Lets start with compact metal halide lamps:
Modernized compact metal halide lamps (double-ended or bipin base) are shrouded with a small diameter quartz outer envelope. This is necessary because of the high temperature involved having the outer envelope is such close proximity to the discharge tube. Maybe they could've used aluminosilicate, but whatever, not what I am talking about. Since the outer envelope is quartz, they dope it with a UV blocking additive so no UV gets through to damage you. This makes sense.
But why don't they just use the additive in the quartz discharge tube itself (excluding CMH obviously)? The would mean you need less special additive to so the same job. This would also open the opportunity for non-extinguishing exposed-rated normal glass bulb MH lamps that don't need a UV shield tube suspended around the discharge tube.
Next is LED halogen retrofits. These are single or double ended LED retrofit lamps for halogen sockets. Like this one:
At first glance this may seem very reasonable. But I assure you it is not. See the molybdenum foil seals at the bottom? That means this lamp is made of quartz. I know why they are doing this, because they are still using their old quartz halogen making equipment to make new LEDs. But I feel like it would be
so simple to modify this kind of equipment to use soda-lime glass, and it would save them a ton of money. Dumet and soda-lime tubing is almost certainly cheaper than molybdenum foil and fused quartz tubing, not to mention the savings associated with switching from oxy-fuel to air-nat gas.
I don't know why I care, but it is just so ridiculously unnecessary that I gotta say something.
Anybody know a lot about quartz who can answer these questions? Thanks
