Exam Question

### (a) Sketch and Describe a Device for Continuous Monitoring of HFO Viscosity
**Concept and Principle of Operation**
The continuous monitoring of Heavy Fuel Oil (HFO) viscosity is crucial for optimal combustion and engine operation. A common device employed for this purpose is a **Vibrating Rod Viscometer**. This device operates on the principle that the dampening effect on a vibrating element, when submerged in a fluid, is directly proportional to the fluid's viscosity. As the viscosity of the HFO changes, the energy required to maintain a constant amplitude of vibration, or the amplitude of vibration for a constant energy input, will vary, providing a measurable signal.
**Construction of a Vibrating Rod Viscometer**