Please follow these instructions to get your monitor ready to correctly display the sRGB images used in these pages. What these instructions do is adjust your monitor to match the sRGB definition as closely as possible.
1. Set the Contrast 
control of the monitor
to maximum.
2. View this chart at a distance of several feet, or squint so that the horizontal lines are not visible.
3. Adjust the Brightness 
control of the
monitor so that the vertical stripes are all the same intensity and
disappear as much as possible. If there seems to be a range in which
they match about the same, set the Brightness at the lowest end of the
range.
It was calculated in floating point and converted to 8-bit file by using the sRGB and dithering algorithims described in this paper.
The gray columns are a ramp from .005 to 5.005. The striped columns alternate 2 pixels of .01 and 2 pixels of 2*G-.01 (where G is the gray to the left). If your monitor is displaying sRGB correctly these should average to G and the columns should be the same luminance.
Unlike most such charts, I used 2 rows per stripe to reduce the effect of blooming that most crt's have. You can reduce this even more by zooming in on the image an integer number of times and covering the screen with diffusion material to blur it.
I also did not use black in the dark stripes to reduce errors caused by ambient light, except at the bottom where the stripe colors are reversed. On my screen it is not possible to adjust the bottom area to match.
The file was saved as a .gif rather then a .png due to some browsers making attempts to gamma-correct .png files.