Final answer:
A pressure gauge is used to show the steam pressure inside the steam boiler, and it's crucial in monitoring systems in autoclaves, nuclear reactors, and coal power plants to ensure safety and efficiency.
Step-by-step explanation:
A pressure gauge shows the steam pressure inside the steam boiler. It is located on or near the top of the steam boiler. Devices like pressure gauges are essential for monitoring the pressure in closed systems such as steam boilers, autoclaves, and nuclear reactors. For instance, in an autoclave, pressure is increased to allow steam to achieve temperatures above the boiling point of water. This is similar to the operation of a pressure cooker in that both are closed systems in which steam does not escape easily, allowing for higher pressure and temperature inside the apparatus, which increases the boiling point of water and cooks food more quickly or sterilizes equipment more effectively.
Pressure gauges can also be found in other thermal systems such as coal power plants and nuclear reactors, where steam pressure must be carefully controlled to ensure efficient and safe operation. Monitoring the steam pressure is critical since it can affect the temperature and efficacy of the heat transfer processes involved in generating electricity or in applications where sterilization or high-temperature steam is necessary.