Gasoline from plastics! My procedure is to have various loads such as oil filled electric heaters, heat lamps, and regular lights in series with watt meters like Kill-a-Watts to measure the power output. Once the system is warmed up, I add more and more power until the engine lugs down or actually quits. The watt meters show the power output. (Might need more than one watt meter.)
If I understand your scheme, you have a high-powered fixed resistor (looks like nichrome wire}, and a solid-state relay that is acting like a light dimmer to control the voltage and thus current into that resistor. The voltmeter measures the voltage and the clamp-on ammeter measures the current. Multiplying current times voltage gives you the power in watts.
Is my interpretation correct? I guess I need to find out more about the solid state relay (SSR).