The stroboscopie light source customarily used for clinical electroretinography has several disadvantages when used for precise laboratory work. The most serious of these are the variance in intensity with speed of flash, the variance in site of flash in the gas-filled tube, and the inability to control the duration of flash.
It is also impossible to accurately coordinate two or more stroboscope units to flash alternately, which is of importance in work recently undertaken.
With these factors in mind, a new light has been devised.
The source of light is a "glow modulator" tube, type R 1131-C, which furnishes a source of light 0.093 in. in diameter and has an instantaneous on and off characteristic, whose intensity can be adjusted through a large range and which can be powered from any one of a number of laboratory stimulators.
It requires a potential of 225 volts to start the light and