In situ isotopic meat grader

Abstract

A meat grader grades meat disposed in a bin of predetermined dimensions wherein the meat extends at least about two feet in all directions. A probe includes a housing containing a scintillation phosphor responsive to gamma rays including 1.46 Mev gamma rays from potassium-40 for producing corresponding light pulses of magnitude systematically related to the energy of the incident gamma rays, and a photomultiplier optically coupled to the phosphor for producing corresponding electronic pulses of magnitude systematically related to the magnitude of said light pulse. The probe is inserted into the meat to dispose the phosphor near the center of the meat. A differential pulse height discriminator selectively responds to such of the electronic pulses as are of a limited range of magnitude including that characteristic of the 1.46 Mev gamma rays by producing corresponding discriminated signal pulses. A counting rate meter counts the number of said discriminated signal pulses in a predetermined time interval to provide a signal indicating gross counting rate. A background counting rate corresponds to the number of discriminated signal pulses in the predetermined period of time occurring with the probe in a corresponding standard environment in the absence of potassium-40. The background counting rate is subtracted from the gross counting rate to indicate net counting rate corresponding to 1.46 Mev gamma rays from potassium-40. Net counting rate is converted into an indication of the relative leanness or protein content of the meat sample.