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    Re: Index Error and Micrometer Drums
    From: Gary LaPook
    Date: 2011 Jan 3, 18:46 -0800

    To ensure good readings one should always bring the body to the horizon in a consistent direction (either up or down) AND one should measure Index Error exactly the same way (ie, if you measured IE by bringing the reflected horizon down to the viewed one, you should always bring bodies down to the horizon)."


    When firing artillery and when firing tank guns we always make the last movement of the gun in the direction that has the greatest resistance to eliminate lash in the mechanism. For example, if it is harder to crank the tube to the left than to the right we would make the last movement to the left. If we overshoot and go to far to the right, for example, then we move the tube back the other way too far and then again move the tube to the right. Although it is not usual to have differences in resistance when using a sextant, if you do then you might want to use the same technique.


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