The manufacture. renovation and repair of laboratory and scientific instruments and of measuring and controlling equipment not elsewhere classified; the fabrication and assembly of cyclotrons, betatron and other accelerators; and the production of surgical, medical and dental equipment, instruments and supplies and of orthopedic and prosthetic appliances. The manufacture of optical instruments for scientific and medical use is classified in group 3852; the fabrication and assembly of radar equipment, X-ray and electric therapeutic apparatus is classified in the appropriate group of major group 383; the production of non-laboratory weighing instruments is classified in group 3825; the manufacture of measuring and dispensing pumps is classified in group 3829; and the fabrication of electrical industrial control devices is included in group 3831.