Miss. Code § 75-31-209
If a tank is designed for use with a gauge rod, a substantial and rigid gauge rod bracket or other suitable supporting elements for positioning the gauge rod shall be so constructed that whenever the rod is placed in engagement with the bracket or supports and released, the rod will automatically seat itself at a fixed height and in a vertical position. When a gauge rod is properly seated on its bracket or supports, there shall be a clearance of at least three (3) inches between the graduated face of the rod and any tank wall or other surface that it faces.
The arrangements shall be such that it shall be impossible to reverse the reading position. The part of the gauge rod bracket which is designed to hold the gauge rod and which comes in contact with the gauge rod shall be sufficiently hardened that, under continual usage or careless handling, it will not become so worn that it will allow the gauge rod to hang to an improper depth in the tank, thereby causing an error in the measure of the milk in the tank.
Miss. Code § 75-31-209