Proportional Caliper

A proportional caliper is used for the rapid and easy determination of percentage of flat particles, elongated particles or both in coarse aggregate fractions of 9.5mm (3/8 in) or larger.
It consists of 6″ x 16″ (152.4 x 406.4 mm) base plate with four rubber feet, two fixed posts and a 13in (330mm) pivoting arm. The positioning of the pivoting arm allows to obtain desired ratio among 1:2, 1:3, 1:4, or 1:5.