An irrigation sprinkler of the type including a nozzle assembly for dispersing water to an area of vegetation by rotation of at least a portion of the nozzle (16, 26) assembly, the improvement comprising: a first magnet connected to the nozzle (16, 26) assembly and adapted to produce a first magnetic field, wherein the first magnet moves in response to a movement of the at least a portion of the nozzle (16, 26) assembly; a sensor unit disposed adjacent to the nozzle (16, 26) assembly for detecting the first magnetic field when the at least a portion of the nozzle (16, 26) assembly is moving, a second magnet connected to the nozzle assembly and adapted to produce a second magnetic field, wherein the second magnet moves in response to the movement of the at least a portion of the nozzle assembly; the sensor unit is further for detecting the second magnetic field when the at least a portion of the nozzle (16, 26) assembly is moving; characterized in that a generally ring-shaped member (20, 22, 24) is adapted to surround the at least a portion of the nozzle (16, 26) assembly and is adapted for cooperative engagement with the at least a portion of the nozzle assembly wherein the first magnet is attached to the generally ring-shaped member; a case adapted to surround at least a second portion of the nozzle assembly, said case having a case seating surface, wherein the nozzle assembly is adapted to move vertically relative to the case from a lower position to an upper position, wherein the generally ring-shaped member (20, 22, 24) is adapted to abut the case seating surface when the nozzle assembly is in the lower position, and wherein the nozzle assembly has a ledge adapted to abut the generally ring-shaped member (20, 22, 24) and to lift the generally ring-shaped member off of the case seating surface when the nozzle assembly is in the upper position. a first magnet connected to the nozzle (16, 26) assembly and adapted to produce a first magnetic field, wherein the first magnet moves in response to a movement of the at least a portion of the nozzle (16, 26) assembly; a sensor unit disposed adjacent to the nozzle (16, 26) assembly for detecting the first magnetic field when the at least a portion of the nozzle (16, 26) assembly is moving, a second magnet connected to the nozzle assembly and adapted to produce a second magnetic field, wherein the second magnet moves in response to the movement of the at least a portion of the nozzle assembly; the sensor unit is further for detecting the second magnetic field when the at least a portion of the nozzle (16, 26) assembly is moving; characterized in that a generally ring-shaped member (20, 22, 24) is adapted to surround the at least a portion of the nozzle (16, 26) assembly and is adapted for cooperative engagement with the at least a portion of the nozzle assembly wherein the first magnet is attached to the generally ring-shaped member; a case adapted to surround at least a second portion of the nozzle assembly, said case having a case seating surface, wherein the nozzle assembly is adapted to move vertically relative to the case from a lower position to an upper position, wherein the generally ring-shaped member (20, 22, 24) is adapted to abut the case seating surface when the nozzle assembly is in the lower position, and wherein the nozzle assembly has a ledge adapted to abut the generally ring-shaped member (20, 22, 24) and to lift the generally ring-shaped member off of the case seating surface when the nozzle assembly is in the upper position.