为消除在测量过程中因圆锥杆受被测材料摩擦力所产生的测量误差,改进了圆锥指数仪设计,将微型力学传感器嵌入到圆锥杆下端,实现了对土壤和青贮玉米饲料压实度的精确测量。试验结果表明,测量2种土壤压实度过程中,原有圆锥指数测量方法因圆锥杆受摩擦力作用所产生的测量误差可忽略不计。而在青贮玉米饲料压实度测量过程中,2种不同紧实度样本中圆锥杆受摩擦力约占压力传感器测量值32.56%和34.05%,当圆锥头不受阻力时,嵌入式力学传感器测量值为零,而压力传感器测量值约为110N和280N,表明原有测量结果存在较大误差。
With the aim to preclude the effect of penetration friction component (PFC) between the penetration shaft and surrounding material during a penetration process, an improved cone penetrometer with a mini force transducer embedded in the cone tip was developed. This kind of cone penetrometer could measure the density of soil and silage correctly. The results showed that the effect of PFC could be negligible in the two kinds of soil samples. But during the density measurement of the two different density chopped maize samples, PFC accounted for 32.56% and 34.05% respectively in the measurement value of force sensor. When there was no resistance on the cone, the measurement value of embedded force sensor was zero, whereas the measurement value of force sensor were about 110 N and 280 N. Appreciable error was found in the original test results for chopped maize.