1. A large storage tank is filled manually by an operator. The operator first opens a valve on a supply
line and carefully watches the level on a level indicator until the tank is filled (a long time later). Once the filling is complete, the operator closes the valve to stop the filling. Once a year the tank is overfilled due to operator distraction. To prevent this incident, an alarm was installed on the level gauge to alert the operator to a high-level condition. With the installation of the alarm, the tank now overfills twice per year. Can you explain why?
Before installation of the alarm, operator is used level indicator to close the valve by manual ( at highest level of... View the full answer