TE241, TE264 or TE259 can be used to measure the opto electronic conversion function. The TE259 is a modified OECF chart following ISO 14524 and ISO 15739 using a horizontal gray scale instead of a circular one. We do highly recommend to have these standards available during measurements to be able to crosscheck the settings of your measurement setup with the standards.
So the standard densities of the patches in the chart are following the mentioned standards. That means that it is NOT a typical gray scale chart with a gamma of 2.2 or a linear gray scale.
The measurements should be done in a totally dark (black) room, otherwise especially the contrast measurements are not leading to correct results due to stray light. If the room has any dominant color walls/floor this could lead to a wrong white balancing. The lens should not have a high level of vignetting, otherwise the measurement results could be wrong due to the fact that the horizontal gray scale is used. If no good lens is available the TE241 or TE264 should be used.
The chart should be used in an illumination device like an Integrating Sphere because a very constant illumination is of a high importance. The testchart can be taken as a full frame scene. In case the camera has more than three MPixels it should slight be defocused to avoid that the halftoning in the chart affects noise measurements. Decreasing the area filled by the chart by zooming out or stepping back is possible too.
If you are using Version 1 of the ISO Noise standard (15739) the exposure level should be set in a way that the brightest patch of the testchart should be just in saturation looking at the camera signal (so for example all pixels in this are have an RGB value of 255/255/255). Many times it is no exactly possible to reach this level only in one patch of the chart but it should not be more than three or four patches in saturation.
Running the image through the OECF analysis of the iQ-Analyzer you get dynamic range, noise behavior, Signal to noise ratio, ISO speed, and white balancing as a result. Especially for some of the noise measurements the standard requires to use several (e.g. ten) images for statistic analysis.