From Episode #114, The Case of the Blind Man's Bluff

It appears that the "black ray" ultra violet lamp used forensically in this episode was a Blak-Ray® B100 Series High Intensity model manufactured by UVP of Upland, California. This model, unlike in the episode, requires an external power source. The coiled-up power cable should have been plugged-in somewhere.

Black Ray Lamp Black Ray Lamp

As seen in the episode. Note the unused coiled-up power cable.

BlakRay Lamp

The current model B-100AR. Similar, but not the same.