What is the full-scale voltage of the 1-5 VDC signal used to monitor the top 8 feet of water in the tank?

• A. 1 V
• B. 5 V
• C. 4 V
• D. 3 V

Answer: (B)

Full-scale voltage is the maximum output of a sensor’s signal range. For a 1–5 VDC signal, the range runs from 1 V at the bottom to 5 V at the top. Monitoring the top 8 feet of water corresponds to the highest point in that range, so the output at that level is the maximum value, 5 volts. The other voltages (1 V, 4 V, 3 V) would represent lower levels within the tank, not the top.