Question 311Motor Plants - Assistant Engineer

The correct answer is B) Final heaters. The viscosimeter would be used to directly control the output of the final heaters. The viscosimeter measures the viscosity of the fuel, which is an important parameter for the proper operation of the final heaters. The final heaters are responsible for maintaining the fuel at the correct temperature and viscosity before it is injected into the engine. By using the viscosimeter to monitor and adjust the final heater output, the fuel can be maintained at the optimal viscosity for efficient combustion. The other answer choices are incorrect because the viscosimeter does not directly control the outflow from the HFO day tank (A), the injector pumps (C), or the HFO purifiers (D). These components have their own control systems that may use viscosity as an input, but the viscosimeter itself does not directly control their output.