I need an example of homeostasis outside of the human body (thermometer, etc).
There are many examples of homeostasis outside the human body. Homeostasis refers to a system that reaches dynamic equilibrium. Continuous changes occur with rapid responses resulting in relatively stable conditions.
One of the easiest examples is a home's comfort system. The thermostat tracks the internal temperature of the house and switches on the appropriate heat or cooling system to maintain the preset temperature.
Another system maintaining homeostasis is the electrical grid. This presents an even better picture. The electrical grid consists of several components. There is the generating station(s), the regulating components and the consumption units. Generating stations may be coal, wind, water or other power stations that produce the raw energy. The regulating components are the switches, circuit breakers and other equipment that directs the flow of energy. The consumption units are the end users, typically homes and businesses. As the consumption units, demand energy the regulating components draw it from the generating station. However, sometimes there are breaks in the transmission such as a blown circuit breaker disrupting the energy supply. To compensate, the regulating components transfer power to other lines or dump it according to the procedures. This ensures power is kept within tolerance limits.