- 2 4 Eeee3089 E1 A A Silo Containing An Unknown Mass Of Grain Is Shown In Figure Q2 Below The Dimensions Of The Base 1 (66.4 KiB) Viewed 13 times
Sensitivity/ gauge factor (G)
Poisson ratio
Nominal resistance
constantan
2.1
0.310
120 ohms
Platinum
6.1
0.385
100 ohms
2. 4 EEEE3089-E1 (a) A silo containing an unknown mass of grain is shown in Figure Q2 below. The dimensions of the base of the silo are shown, along with the location of the strain gauge, which is positioned on one of the 4 silo legs. After the grain was added to the silo the change in the length of each silo leg was 159μm. Calculate the strain in each leg of the silo, give your answer in micro-strain. [3] Grain Leg length, L= 1m Leg width, d=100mm Leg cross section = circular Leg material, Steel, E=200GPa L Figure Q2 Grain silo cross section. (b) If the Young's modulus E of the steel leg material is 200GPa, how many kilograms of grain was added to the silo in Q2(a)? [6] (c) Table 1 has two strain gauge devices which could be used on this silo. For each of these devices, what percentage of the gauge factor is due to the term depending on the change in resistivity with strain? [4]