Crush Strength Apparatus with a Photocell Detection Unit

An apparatus utilizing a photocell detection system was designed and built to measure the force required to crush a spherical particle 0.05 to 0.5 mm in diameter. The force applied to the particle causes a variation in light area on two matched photocells. The signal from the unbalance in the photocells is recorded without amplification on a millivolt recorder as the particle is crushed. Standardization is accomplished by placing known weights on the apparatus and measuring the displacement on a recorder. The apparatus can be used to measure crush strengths from 0.080 to 2500 g.