Holophane QSS to a TRT Aspect Mini

I recently purchased some 400watt MH gear and would like to know if it’s safe to run the lamp out of an enclosure. I do know that MH lamps have the tendency to sometimes explode apon EOL.

All HID lamps (excluding HPS, as they run at below atmospheric pressure) carry some nonzero risk of explosion. Even mercury lamps. In practice, it is rather minor for a short test run. Be careful with heavily used ones with blackened or bulged arctubes.

Surprisingly, old style high powered MH lamps like 400W multi-vapor tend to run at rather moderate pressures and are less risky than some smaller MH in 20, 35 and 70 watts!

There are open rated lamps having an extra protection shroud around the arctube for the case it explodes, which can be run with a peace of mind openly. Rare in high wattages.

IIRC, dim pink fluorescent tube is due to mercury starving, so only the buffer gas is lit up. On some tubes you may get a purple color too! Yea you can call them weird tubes

that we call dim pink fluoros "weirded out" because no one knows why they do that.

Yes, as long as the lamp is a 4W, 6W, or 8W tube, an FS-5 or equivalent starter should work just fine at any of those supply voltages. I believe the important part is the lamp's voltage, not the main supply voltage, so there shouldn't be a difference.

Hi, I would like to know if the starter needed for a single lamp ballast for a F4, F6, F8 lamp is the same or different for each of the following ballasts: 120V ( Robertson L48) , 240V ( Robertson L4835 ) , and 277V ( Robertson L6827 ).

Before they knew the dangers of radium did they use it on darkroom equipment(scales, dials and meters, switches etc)? And how useful would it have been, when the safelight was not used?

If it is an exposed rated lamp, then I would say yes this is probably safe.

But assuming it is an enclosed rated lamp (as most are), then I would say maybe. If the lamp is used (or you don't know it's history), I would not at all run it in the open. Technically even a brand new lamp can explode with a severe enough manufacturing defect, but I haven't seen that.

Explosion is always a risk, but if you shield the lamp or shield yourself you should be relatively safe even with an old lamp.

Running them vertically reduces the likelihood.

I recently purchased some 400watt MH gear and would like to know if it’s safe to run the lamp out of an enclosure. I do know that MH lamps have the tendency to sometimes explode apon EOL.