Those quartz tubes are not designed to withstand cooling to such low temperatures.
Some have a heating element inside a quartz tube.
A rising red thread in a quartz tube marked off the disappearing seconds.
The length of the quartz tubes are different.
The commonly used quartz tubes are made of 99.9% SiO.
After that, powdered sulfur was placed upstream of the quartz tube in the furnace about 15 cm away.
The normal quartz tube has impurities that block the 185 nm wavelength.
Well, Brad won a lot of races in the old shell using home-lined quartz tubes.
Only the thing won't work in quartz tubes- burns 'em out.
To start the discharge a high-voltage pulse is applied on an electrode inside the quartz tube.