A liner bolt for securing a liner to a mill, the liner bolt comprising a head and a shank extending therefrom, the shank having an external thread thereon, and having a bore therein extending from its free end. A selected reference cell and a non-used memory cell are read simultaneously, and a signal read from the reference cell is compared to a signal read from the non-used memory cell. The sprinkler may include a flow rate adjustment device that may be adjusted by actuation or rotation of an outer wall portion of the sprinkler.