The best way to get the numbers to calm down and become more readable is to enable averaging. You can do this by pressing the "Average" hard key on the far right side of the VM700T front panel. The default number of samples to average over is typically 32 but this can be changed to any value between 1 and 256 by pressing the "Menu" button, then touching the "Average Num" softkey in the lower left corner and using the general purpose knob to adjust the number of samples to average over. If this does not produce a stable enough value to read you can also use the freeze button to freeze the display long enough to record these values. However, if averaging over 256 samples still does not yield a stable value there may be something wrong with your signal and further investigation might be required.