Lamps

Our Compact Fluorescent Lamp (CFL) setup

We use the setup shown to the left to calibrate the wavelength axis of our spectrometers. Fluorescent lamps gives off good visible line spectra making them ideal for calibration. The bulb, socket and switch hardware were purchased at the local home improvement store. The box in the background fits over the lamp. The orange square covers a hole where light contacts the fiber optic that connects to the spectrometer.

Incandescent lamp

Incandescent bulbs give off good broad band visible light. This lamp has a 12 volt tungsten halogen bulb I purchased online and is powered by a 12 volt 1 Amp "wall wart" AC / DC converter.

The guts of the incandescent lamp

The lamp plugs into a 1 amp AC to 12 volt DC converter. The housing is an electrical outlet box from my local home center.

A deuterium lamp requires more effort to fabricate

The lamp and power supply can be purchased online from a vendor on Alibaba.com. I had the aluminum block machined.

A DIY light source for UV-vis spectroscopy

Shown below are photos of a working UV-vis source. In the left hand photo, the base of he deuterium lamp (with its red and black wires) can be seen sticking out of the near edge of the aluminum block. The UV lamp has a hole that allows light from a tungsten halogen lamp to pass though co-linearly. The visible lamp is housed in a piece of copper pipe bolted to the aluminum block. I don't remember how powerful the visible lamp is but I used a dedicated 12 volt source to run it.

This was built mostly as a proof of concept and did not see a lot of day-to-day work. The problem with this design is that the end panels of the box are plastic and the lamps and electronics generate a lot of heat. If I am recalling correctly, I ended up putting a piece of tile backer-board between the aluminum block and the front end panel. That kept the plastic from melting, but I am still a little wary of running this thing.

In the right most photo, you will see a silver thermocouple projecting into the front housing. This was taken when I was doing a thermal stability test. The results of that test are in a lab notebook somewhere, probably in a dump. As I recall (don't quote me), the interior warmed up to about 60 C and stayed there for a few hours before I ended the test.