A method of measuring the temperature of a sheet material in which the sheet material is arranged such that it forms at least one side of a cavity so as to enhance the effective emissivity of the sheet material in the vicinity of the cavity. The processor is operable to determine a first and second edge of a dairy livestock. The apparatus is configured with control logic to issue an alert if the integrity of the monitored circuit has been compromised. The holding member includes a periphery formed with a plurality of recesses. The discharge transistor is connected between the first node and the second node. The golf club head preferably has a volume ranging from 420 cubic centimeters to 470 cubic centimeters.