Phase rulers (called rotation rulers in PicoScope Automotive) are a set of lines that can be drawn over a scope trace to help measure phase angles. This is particularly useful for analyzing rotating machines and AC power waveforms. Phase rulers can be displayed by clicking More > Rulers and switch Phase rulers to the On position, then drag the start and end rulers to the desired width. From this menu you can change the full cycle boundaries to 360°, 720°, 100% or a custom range. You can also add partitions to divide up the full cycle to show 90°, 180° and 270° as points to highlight.