Op sensors

1. Using Multisim, design a system using the photoconductive cell shown in the figure below to measure and display light intensity. Make the design such that 20 to 100mW/cm2 produces an output of 0.2 to 1.0V. What is the readout error when the intensity is 60mW/cm2? Show all calculations and Multisim results.

2. For the turbidity system show in Figure 2 below, two matched photoconductive cells are used in R vs. IL as given in Figure 3 below. Design a signal-conditioning system that outputs the deviation of the flowing system turbidity in volts and triggers an alarm if the intensity is reduced by 10% from the nominal of 15mW/cm2.

Figure 2

Figure 3