"The Wagner Turbidimeter determines the fineness of portland cement by measuring the specific surface area. A constant light source passes through a suspension of the cement and is detected by a photoelectric cell. Values are correlated to particle diameters measured of 50, 45, 40, 35, 30, 25, 20, 15, 10 and 7.5 micrometers. Turbidity changes as the particles settle from suspension. Turbidity is related to specific surface area, computed as described in ASTM and AASHTO procedures.","The Turbidimeter is supplied with photoelectric cell, light source, heat absorbing device, light filter, shield, and sedimentation tank in metal cabinet with wall mounts and adjustable shelf. Timing burette with stand, microammeter, stirring apparatus, wet sieving assembly with No. 325 sieve, flasks, test tubes, and instruction book are also included. A 6V storage battery or other constant emf source is required, but not included. For calibration, order BS-50, NIST Portland Cement standard reference material separately. Est. Ship Wt.: 110lb (68kg)."