The adjustable Spectrum Tube Power Supply is designed to be very easy to use, ideal for classrooms and school laboratories. This power supply can accommodate tubes of varying lengths, which is very helpful if you have a mixed collection!
 
To adjust the length, simply loosen the brass nut on the back of the column, slide the top receiver into the desired position, and tighten the nut. It’s that easy.
 
To put a tube in the power supply, place one end in the lower receiver, and press down the spring there. This should give you enough clearance to slide the top portion of the tube into the upper receiver.
 
This Power Supply will fit spectrum tubes with a diameter up to 2.5cm.
 
What are spectrum tubes, and why do we need a separate power supply for them?
Spectrum tubes are small glass vessels which are filled with a specific gas, and are then sealed. Electrodes are added to the ends of the tubes. When electricity is passed through the tube, it excites the molecules of the gas, causing them to emit light. However, all gases are not created equal, and different elements will produce a different light spectrum.
Argon, for example, produces a purplish light, while hydrogen is redder.