Direct-Residual Shear Apparatus, also Direct Shear Apparatus
S2215A is one of several all digital direct shear and direct-residual shear systems, now being offered. Principal distinguishing features are pointed out under S2215A, but we believe a few deserve more scrutiny.
1. Using a load cell to measure normal load eliminates errors caused by always present friction in the loading system. With a load cell only the force being applied to the specimen is measured. At time of catalog preparation, only Geotest offered this feature.
2. ASTM D3080 states in paragraph 6.4.3 that the weight of the top shear box should be less than 1 percent of the applied normal load. Only the Geotest direct shear machines, as far as we know, comply to this requirement. A unique system developed by our chief engineer, Arthur Patten, eliminates all of the weight of the upper shear box.
3. Using 2 cylinders to apply normal load allows loads as low as 2 lbf (10N) and as high as 2,000 lbf (10kN) to be applied. This permits laboratories using the Geotest machine to apply for lower loads than possible with any other machine on the market.
4. Automatic data acquisition on S2215A is standard and does not require any additional purchase (please see data acquisition systems in the category data collection/software for full description). No internal storage capacity is included with Geotest apparatus. Due to the wide availability and present low cost of PCs, this was no longer considered to be of any advantage to the user.
5. Our PC controlled apparatus, S2216 allows the operator to control all phases of the test procedure from a PC.