Now that we know a little about the four parts of a thermal system, let's observe a thermal system in action. In Figure 12a, the workload is a tank filled with water and a mild cleaning solution. A sensor is placed in the water to monitor water temperature. The sensor is connected to a temperature controller. A heater is also connected to the temperature controller and placed under the tank. What happens when the thermal system is switched on? What do you suspect? Read the captions in Figure 12 to find out! We have just observed a simple thermal system in action! It is true that thermal systems do get more complex than this simple example (like Figure 14). However, you will AWAYS understand how a thermal system is working if you keep things simple! Break it down into its component parts: work load, heater,sensor and control. Observe what each part is oing and how it is doing it. This makes you very valuable to the customer, because you can offer better solutions through better analysis.