How sensitive can the IMD numbers reflect the SRA changes?

How sensitive can the IMD numbers reflect the SRA changes? Just about 1/4 of an mm's adjustment on the Graham Phantom II, the resulting differences in measurements are quite obvious as shown below. The sound also becomes much more refined with darker background and lower perceived distortion.

IMD反應SRA的改變有多敏感？我長久未去變動設定的 Lyra Kleos 裝在 Graham Phantom II，很早以前就用顯微鏡調到SRA約92度。圖1是顯示調整後唱臂的高度微調刻度在7.75。而未動之前在9左右，所以大概是降低1/4個 mm，下方的粗刻度則是幾乎看不出差別。圖2是還沒動之前，用 AnalogMajik 測得的 IMD數據。圖3是微小調整唱臂高度後，測得的較佳IMD。這時，音質的細膩度與背景安靜度的確是得到相當的提升。