Shown below is a student's answer from last year's exam depicting a block diagram of a flame atomic absorption spectrometer for measuring calcium. The path that light travels is indicated by (→), and the path for voltage or current by (==). Modify the diagram to correct the errors by labeling each one, describe what is wrong, and suggest the proper configuration. You can add or subtract any extra components that are necessary. Be sure to account for background absorption of molecules that may be present in the flame.