The principle of a shear force measuring instrument is to insert a shaft with blades into the soil and then rotate it at a certain speed and force. The force is measured at the point of soil tension fracture, and the shear force at that measurement point can be calculated based on this. The maximum shear force that the soil can withstand can be measured using an on-site shear force measuring instrument. Suitable for laboratory and on-site use. The measurement result of shear force can be clearly read from the scale ring. If the soil is relatively soft, there is no need to drill holes in advance. False blades can be used to determine the frictional force of the extension rod. The standard device includes: an on-site shear force measuring instrument, which should have three complete blades (16 × 32, 20 × 40, and 25.4 × 50.8 millimeters respectively) and a fake blade, various extension rods, wrenches, and a shipping bag. Explanation: The principle of the shear force measuring instrument is very simple, which is to insert a shaft with blades into the soil and then rotate it at a certain speed and force. The force is measured at the point of soil tension fracture, and the shear force at that measurement point can be calculated based on this. Technical specifications: On site shear force measuring instrument, standard system can measure up to 200kPa (20t/m2) at a depth of 3 meters.