9.7 The unbonded strain gauge accelerometer of Figure 8.20 and Section 9.1.2 has a natural fre- quency of 175 Hz and an input range of 0 to 5g. Given that the strain due to prestressing is twice the maximum acceleration-induced strain, use the strain gauge data given below to calculate the range of the bridge output voltage. Resistance Gauge factor Maximum current = 120 2 = 2.1 = 50 mA Length at zero acceleration = 2.3 cm Figure 8.20: the Unbonded strain gauge accelerometer. 2 eo-e eo+e m 3 eo+e x=0