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Proportional Calipers

Select Item: $230.00 HM-38B  Proportional Caliper, 4-Station $173.00 HM-38R  Proportional Caliper, Budget Specify Quantity:     Estimated Shipping Weight: 8.0 pounds   3.6 kilograms Product Manual Test Methods ASTM D 4791 Recent Items Proportional Caliper, Budget Reflux Extractor Kit, 1000g Capacity, 115V/60Hz Coarse Aggregate Void Content Apparatus Specific Gravity Bench Complete w/o Tank NCAT Asphalt Field Permeameter Kit

HM-38R pictured

HM-38R

Shape characteristics of coarse aggregates are important to performance of materials or mixes. HM-38R and HM-38B Proportional Calipers are timesaving devices. Use either for rapid determination of percentages of flat and elongated particles in coarse aggregate fractions of 3/8in (9.5mm) or larger. Both units are constructed of durable aluminum, precision tooled for accuracy.

For shape determination of flat particle sizing, set the width of a particle in the larger end of the Caliper, then tighten the pivot screw. Without adjusting the Caliper, determine the thickness of the same particle in the smaller measuring end of the Caliper. If the particle fits within the smaller gap, it is considered flat. Elongated particle determination uses the same steps. If the particle is larger than the small measurement in both situations then the particle is considered neither flat nor elongated.

HM-38R Budget Caliper consists of a 6x16in (152x406mm) base plate with two fixed posts and a 13in (330mm) pivoting arm mounted between the posts so that there is an opening at each end of the arm. The pivoting arm adjusts by securing a pivot screw at one of four threaded positions to provide end opening ratios of 1:2, 1:3, 1:4, or 1:5. Est. Ship Wt.: 8lb (4kg).

HM-38B Four-Station Caliper is similar, but provides openings for all four ratios simultaneously, without the need to reposition the pivot screw. Moveable posts are also replaceable. Est. Ship Wt.: 8lb (4kg).