Example 12.1 The output voltage from a sensor varies from 0.35 to 0.7 V as the
process variable varies from low to high over its measurement range. However, the
sensor output goes to equipment that requires a voltage from 0 to 10 V for the range
of the variable. A circuit for changing the output levels is shown in Fig. 12.1b. The
negative input to the amplifier is set at 0.35 V to offset the sensor minimum level to
give zero out at the low end of the range. The gain of the amplifier is set to 28.6 giving
10 V output with 0.75 V input, i.e., 10/(0.7 − 0.35) = 28.6. Note the use of impedance
matching buffers that would be used in instrumentation.