Abstract: The intensity output of a monochrome interlaced video monitor typically used in medical imaging may be tested as follows. The video card of a computer is controlled to output equal video intensity levels of red, green, and blue for a time sequenced series of different levels. These video signals are combined and attenuated such that the peak level of the series is about 700 mV, which is the industry standard for peak white on a monochrome monitor. The sync pulses from the video card are adjusted to about -300 mV, which is the industry standard for sync pulses driving a monochrome video monitor and are combined with the combined video signal to produce an intensity test signal for driving the monitor. The video card is controlled to produce a high line rate to drive video monitors having an (approximately double) high line rate and to produce a low line rate to drive video monitors having (an approximately double) low line rate.